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Georgia Tech
1.
Guang, Zhe.
Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses.
Degree: PhD, Physics, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/58133 
► Today one of the frontiers in light measurement is to measure ultrashort pulses from ultrafast laser systems, which demonstrate extremely fast temporal variations, and are…
(more)
▼ Today one of the frontiers in light measurement is to measure ultrashort pulses from
ultrafast laser systems, which demonstrate extremely fast temporal variations, and are necessarily associated with large spectral bandwidths by Fourier transform. In addition to the temporal and spectral structures, ultrashort pulses can also be complex in space. Especially, the field can have spatiotemporal couplings which relate pulse temporal profile to spatial coordinates. Therefore, a complete spatiotemporal measurement technique is needed. In this work, we demonstrate our study on measuring complex ultrashort pulses by development of a method, called Spatially and Temporally Resolved Intensity and Phase Evaluation Device: Full Information from a Single Hologram (STRIPED FISH). Based on digital holography, this simple single-frame method can measure the complete spatiotemporal intensity I(x,y,t) and phase ϕ(x,y,t) of pulses at a particular z-plane. By experiments, we investigated sub-picosecond chirped pulse beating, pulses from multimode optical fibers,
ultrafast lighthouse effect and so on, using STRIPED FISH. We also performed numerical simulations to understand the effects of different spatiotemporal distortions on STRIPED FISH trace. With its improved apparatus, processing algorithm, and display method, STRIPED FISH offers a simple and compact solution to monitor, measure, and display spatiotemporal structures in ultrashort pulses.
Advisors/Committee Members: Trebino, Rick (advisor), Adibi, Ali (advisor), Curtis, Jennifer (advisor), Chapman, Michael (advisor), Jiang, Zhigang (advisor).
Subjects/Keywords: Ultrafast optics; Ultrafast measurement
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APA (6th Edition):
Guang, Z. (2016). Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58133
Chicago Manual of Style (16th Edition):
Guang, Zhe. “Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses.” 2016. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/58133.
MLA Handbook (7th Edition):
Guang, Zhe. “Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses.” 2016. Web. 06 Mar 2021.
Vancouver:
Guang Z. Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/58133.
Council of Science Editors:
Guang Z. Single-frame complete spatiotemporal measurement of complex ultrashort laser pulses. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58133
2.
DEB, SANGHAMITRA.
Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems.
Degree: PhD, Chemistry, 2012, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:297584/
► Understanding of structural, reaction and charge transfer dynamics of any molecular system has been a challenge for both modern spectroscopists and theorists. The structural changes…
(more)
▼ Understanding of structural, reaction and charge
transfer dynamics of any molecular system has been a challenge for
both modern spectroscopists and theorists. The structural changes
after an excitation can be very fast, playing out on time frames of
femtoseconds. Structural changes in large molecules such as
proteins or enzymes are induced by seemingly small triggers, for
example a simple carbon – carbon bond rotation, charge transfer, a
hydrogen bond formation or a simple bond dissociation. Our studies
of model systems in molecular beams help us to understand these
structural changes without any interference from other effects. In
our approach we use time resolved photoelectron spectroscopy
coupled with mass spectrometry to explore dynamics in molecular
Rydberg states. Using Rydberg states as intermediates simplifies
the spectra by removing the vibrational components, while their
structural sensitivity brings out important features of
ultrafast
molecular dynamics. The transition from the intermediate Rydberg
state to the ion state gives rise to sharp peaks, forming the basis
of Rydberg fingerprint spectroscopy (RFS). The time-resolved RFS,
complemented with the theoretical calculations, provide an almost
complete two-dimensional picture of the structural dynamics of the
model systems. The model systems we choose to study different
aspects of structural dynamics are: Triethylamine and
N,N,N’,N’-Tetramethylethyl-enediamine for conformational dynamics;
N,N’-Dimethylpiperazine, N-methylmor-pholine and related molecules
for charge transfer dynamics; and N,N’-Dimethyliso propylamine and
N,N,N’,N’-Tetramethylethylene -diamine for cluster dynamics and
proton transfer.
Advisors/Committee Members: Weber, Peter (Director), Stratt, Richard (Reader), Doll, Jimmie (Reader), Wang, Lai-Sheng (Reader).
Subjects/Keywords: Ultrafast Dynamics
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APA (6th Edition):
DEB, S. (2012). Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:297584/
Chicago Manual of Style (16th Edition):
DEB, SANGHAMITRA. “Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems.” 2012. Doctoral Dissertation, Brown University. Accessed March 06, 2021.
https://repository.library.brown.edu/studio/item/bdr:297584/.
MLA Handbook (7th Edition):
DEB, SANGHAMITRA. “Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems.” 2012. Web. 06 Mar 2021.
Vancouver:
DEB S. Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems. [Internet] [Doctoral dissertation]. Brown University; 2012. [cited 2021 Mar 06].
Available from: https://repository.library.brown.edu/studio/item/bdr:297584/.
Council of Science Editors:
DEB S. Ultrafast structural dynamics of flexible, Rydberg excited
molecular systems. [Doctoral Dissertation]. Brown University; 2012. Available from: https://repository.library.brown.edu/studio/item/bdr:297584/
University of Alberta
3.
Purschke, David N.
Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses.
Degree: MS, Department of Physics, 2016, University of Alberta
URL: https://era.library.ualberta.ca/files/cmg74qm424
► Over the last 5 years, tilted pulse-front terahertz (THz) generation has opened the door to new studies of nonlinear dynamics in a variety of materials.…
(more)
▼ Over the last 5 years, tilted pulse-front terahertz
(THz) generation has opened the door to new studies of nonlinear
dynamics in a variety of materials. With access to strong electric
fields that turn on and off over picosecond timescales exciting new
possibilities exist to control light-matter interaction. We have
developed a new intense THz pulse source, with a peak electric
field of 230 kV/cm for exploring nonlinear dynamics in
semiconductors. Here, we study the effects of THz pulses on
semiconductor photoluminescence (PL). When a femtosecond optical
and single-cycle intense THz pulse are simultaneously incident on a
direct-gap semiconductor, the THz pulse enhances high energy and
quenches low energy PL. However, with time delays larger than 1 ps,
no modulation of the PL occurs. We have systematically studied the
THz-pulse-induced change in PL (THz- _PL) over a wide range of THz
energies and photoexcitation densities in gallium arsenide (GaAs)
and indium phosphide (InP) to help understand the mechanism. In
most cases, the quenching dominates and there is integrated PL
quenching (PLQ). With increasing photoexcited carrier density, the
fractional quenching decreases, while the enhancement increases,
and less integrated modulation occurs. At high excitation density,
by changing the temporal profile of the photoexcitation pulse, the
enhancement can be made to dominate and there is integrated PL
enhancement (PLE). The origin of this behaviour has to do with the
redistribution of carriers in phase space by the strong electric
field of the THz pulse. In real space, oppositely charged electrons
and holes are spatially separated. In momentum space, hot electrons
scatter to satellite valleys, increasing the rise-time of the PL,
slowing carrier diffusion, and releasing a large number of
high-wavevector phonons. Despite our understanding of these
processes, a precise description of the THz-ΔPL is still not
completely clear. Possible explanations for these effects are
discussed, including suppression of stimulated emission, enhanced
surface recombination, and non-radiative recombination involving
intervalley phonons.
Subjects/Keywords: terahertz; ultrafast; luminescence
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APA (6th Edition):
Purschke, D. N. (2016). Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/cmg74qm424
Chicago Manual of Style (16th Edition):
Purschke, David N. “Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses.” 2016. Masters Thesis, University of Alberta. Accessed March 06, 2021.
https://era.library.ualberta.ca/files/cmg74qm424.
MLA Handbook (7th Edition):
Purschke, David N. “Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses.” 2016. Web. 06 Mar 2021.
Vancouver:
Purschke DN. Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses. [Internet] [Masters thesis]. University of Alberta; 2016. [cited 2021 Mar 06].
Available from: https://era.library.ualberta.ca/files/cmg74qm424.
Council of Science Editors:
Purschke DN. Modulation of Semiconductor Photoluminescence with Intense
Terahertz Pulses. [Masters Thesis]. University of Alberta; 2016. Available from: https://era.library.ualberta.ca/files/cmg74qm424
4.
Wang, Kai.
Ultrafast Optical Pulses: Synthesis and Applications.
Degree: 2013, Texas Digital Library
URL: http://hdl.handle.net/1969;
http://hdl.handle.net/2249.1/66823
► This dissertation is devoted to ultrafast waveform synthesis using coherent Raman sidebands with the assistance of pulse shapers based on acousto-optic programmable dispersive ???lter (AOPDF)…
(more)
▼ This dissertation is devoted to
ultrafast waveform synthesis using coherent Raman sidebands with the assistance of pulse shapers based on acousto-optic programmable dispersive ???lter (AOPDF) or deformable mirror (DM). Ultrashort optical science has encompassed the realm of electronic and chemical processes taking place on the few femtosecond-to-attosecond timescale. Molecular modulation is a technique that has been developed to produce
ultrafast pulses based on broadband coherent Raman scattering, which provides the required optical bandwidth. This technique is capable of producing a pulse whose duration can be shorter than one optical ???eld cycle in the visible-UV range, providing a potential for non-sinusoidal ???eld synthesis.
We produce the coherent Raman sidebands in a Raman-active crystal driven by two-color femtosecond laser pulses. With the assistance of a pulse shaper based on AOPDF, we report the phase control of the ultrabroad spectrum, aiming to synthesize non-sinusoidal waveforms. The setup allows for both coarse, manual phase adjustments and programmable ???ne-tuning of spectral phases. A ???at spectral phase across these 5 frequency-separated sub-bands is achieved, which implies generation of isolated 2 to 3 optical-cycle pulses.
The energy of the
ultrafast waveform produced in this setup is limited by the damage threshold of the pulse shaper. In order to obtain high energy
ultrafast waveforms, we design a re???ection scheme using spherical mirrors to combine the Raman sidebands. The sidebands and the driving pulses are refocused back to the Raman crystal and the relative spectral phases are retrieved from an interferogram based on nonlinear Raman interaction. Furthermore, using a DM to adjust the spectral phases, we demonstrate that our setup is capable of synthesizing
ultrafast waveforms using the coherent Raman sidebands.
We explore an additional ultrashort pulse generation technique, theoretically. We investigate formation of resonant dispersive waves (RDW) in photonic crystal ???bers (PCF). Our simulation shows that with an input of two pulses, or a broadband chirped pulse in a PCF, RDW could form a su???ciently short pulse in the UV region, which could be a new method to obtain the ultrashort UV pulse.
In addition to studying methods for production of ultrashort pulses, we explore areas where such pulses can be utilized. The ???eld of
ultrafast optics is highly interdisciplinary, with a wide range of applications. We report two experiments with femtosecond laser pulses: 1) we demonstrate a scheme which achieves sub-di???raction imaging of remote objects by using femtosecond laser ???laments. The use of laser ???laments for imaging is destined to have applications in many environments. Achieving super-resolution has become a scienti???c imperative for remote imaging of objects and scenes needing increased detail and has motivated the development of various laser-based techniques. 2)…
Advisors/Committee Members: Sokolov, Alexei V (advisor).
Subjects/Keywords: ultrafast waveform synthesis
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APA (6th Edition):
Wang, K. (2013). Ultrafast Optical Pulses: Synthesis and Applications. (Thesis). Texas Digital Library. Retrieved from http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66823
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Kai. “Ultrafast Optical Pulses: Synthesis and Applications.” 2013. Thesis, Texas Digital Library. Accessed March 06, 2021.
http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66823.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Kai. “Ultrafast Optical Pulses: Synthesis and Applications.” 2013. Web. 06 Mar 2021.
Vancouver:
Wang K. Ultrafast Optical Pulses: Synthesis and Applications. [Internet] [Thesis]. Texas Digital Library; 2013. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66823.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang K. Ultrafast Optical Pulses: Synthesis and Applications. [Thesis]. Texas Digital Library; 2013. Available from: http://hdl.handle.net/1969; http://hdl.handle.net/2249.1/66823
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
5.
Yang, Fan.
Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics.
Degree: PhD, Physics, 2009, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:179/
► We present our work on the study of gigahertz ultrasound propagation in water by using the picosecond ultrasonic technique. An advanced opto-acoustic detection scheme through…
(more)
▼ We present our work on the study of gigahertz
ultrasound propagation in water by using the picosecond ultrasonic
technique. An advanced opto-acoustic detection scheme through the
use of a Fabry-Perot resonant optical cavity was developed in order
for the weak opto-acoustic signals caused by the sound pulses in
water to be efficiently detected with a reasonable signal to noise
ratio. By using this advanced detection technique, we investigated
the acoustic attenuation and dispersion in water at different
temperatures. Our experimental results indicate that, in the
frequency range up to 11 GHz, there is no acoustic dispersion in
water. Over this frequency range, the acoustic attenuation in water
is found to be proportional to the square of the frequency. We also
report our picosecond acoustic interferometry measurement results
of the velocity and attenuation of sound waves in water at about 5
GHz. In addition to the study of sound waves in unbounded water, we
studied ultra-short sound pulse propagation in water confined in
nanometer scale deep trenches. We found that the sound pulses
traveling through the deep trenches have different temperature
dependence from the sound pulses reflected by the tops of the
semiconductor lines. Our further investigation shows that this
effect is caused by the strong shear viscous force acting on the
sound pulses as they travel down the trenches.
Advisors/Committee Members: Maris, Humphrey (director), Nurmikko, Arto (reader), Valles, James (reader).
Subjects/Keywords: ultrafast; laser; acoustics
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APA ·
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APA (6th Edition):
Yang, F. (2009). Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:179/
Chicago Manual of Style (16th Edition):
Yang, Fan. “Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics.” 2009. Doctoral Dissertation, Brown University. Accessed March 06, 2021.
https://repository.library.brown.edu/studio/item/bdr:179/.
MLA Handbook (7th Edition):
Yang, Fan. “Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics.” 2009. Web. 06 Mar 2021.
Vancouver:
Yang F. Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics. [Internet] [Doctoral dissertation]. Brown University; 2009. [cited 2021 Mar 06].
Available from: https://repository.library.brown.edu/studio/item/bdr:179/.
Council of Science Editors:
Yang F. Study of Gigahertz Ultrasound Propagation in Water Using
Picosecond Ultrasonics. [Doctoral Dissertation]. Brown University; 2009. Available from: https://repository.library.brown.edu/studio/item/bdr:179/
6.
Cheng, Xinxin.
Ultrafast Charge Localization and Delocalization in
Diamines.
Degree: PhD, Chemistry, 2015, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:419416/
► Charge transfer (CT) is one of the most important and most general reactions that exist in living cells, solar energy conversion devices, chemical synthesis and…
(more)
▼ Charge transfer (CT) is one of the most important and
most general reactions that exist in living cells, solar energy
conversion devices, chemical synthesis and many other processes.
Understanding the mechanisms and conditions of CT provides insights
about the processes involved in charge transportation and provides
guidance for designing CT-related devices. Because there are two
nitrogen atoms in one molecule, diamine molecules with different
numbers and lengths of carbon bridges between the two nitrogen
atoms have been explored as prototypes to study the electron lone
pair interaction. Two types of interactions, the
through-bond-interaction and through-space-interaction for the
electron lone pairs in the diamine molecules have been proposed
theoretically and discovered by experiments. Time-resolved Rydberg
Fingerprint Spectroscopy (TR-RFS) is a powerful tool to probe the
structural dynamics in real time, especially when the system is
hot. This dissertation focuses on the structural dynamics studies
of N, N’-Dimethylpiperazine and N, N, N’,
N’-Tetramethylethylenediamine using
ultrafast TR-RFS combined with
quantum chemistry calculations. The electron lone pair interactions
and the sequential CT process were found to be very dependent on
the structures. The time constants for the structural dynamics and
CT process were determined. The large time constants were
attributed to the slow nuclear motions of the molecule required to
find the proper structure where the electron lone pairs can
interact strongly and the charge can transfer from one nitrogen
atom to the other.
Advisors/Committee Members: Weber, Peter (Director), Wang, Lai-Sheng (Reader), Doll, Jimmie (Reader).
Subjects/Keywords: Ultrafast Structural Dynamics
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APA (6th Edition):
Cheng, X. (2015). Ultrafast Charge Localization and Delocalization in
Diamines. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:419416/
Chicago Manual of Style (16th Edition):
Cheng, Xinxin. “Ultrafast Charge Localization and Delocalization in
Diamines.” 2015. Doctoral Dissertation, Brown University. Accessed March 06, 2021.
https://repository.library.brown.edu/studio/item/bdr:419416/.
MLA Handbook (7th Edition):
Cheng, Xinxin. “Ultrafast Charge Localization and Delocalization in
Diamines.” 2015. Web. 06 Mar 2021.
Vancouver:
Cheng X. Ultrafast Charge Localization and Delocalization in
Diamines. [Internet] [Doctoral dissertation]. Brown University; 2015. [cited 2021 Mar 06].
Available from: https://repository.library.brown.edu/studio/item/bdr:419416/.
Council of Science Editors:
Cheng X. Ultrafast Charge Localization and Delocalization in
Diamines. [Doctoral Dissertation]. Brown University; 2015. Available from: https://repository.library.brown.edu/studio/item/bdr:419416/
7.
Bao, Jie.
Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems.
Degree: PhD, Chemistry, 2011, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:11189/
► Understanding the molecular structural dynamics of highly excited, large molecules on various dynamics levels has been a challenge for both experimentalists and theorists. We approach…
(more)
▼ Understanding the molecular structural dynamics of
highly excited, large molecules on various dynamics levels has been
a challenge for both experimentalists and theorists. We approach
this task in three ways using specialized
ultrafast photoelectron
spectroscopy and mass spectrometry techniques: Rydberg Fingerprint
Spectroscopy simplifies and clarifies the spectroscopic transitions
of large molecules by removing the vibrational components while
keeping its structural sensitivity; Photoelectron Vibronic
Spectroscopy is specialized at discriminating vibrational motions;
and when combined with mass spectrometry, these spectroscopies are
able to reveal molecular dynamics on various levels unambiguously.
We applied these techniques to the study of stilbenes and
azobenzene molecular systems, an important set of prototypical
photodynamic molecules. We successfully uncovered the structural
dynamics of these molecules on their high lying electronic states.
Our results also revealed an interesting correlation of the
molecular structural dynamics with the electronic character of the
excited electronic states.
Advisors/Committee Members: Weber, Peter (Director), Doll, Jimmie (Reader), Rose-Petruck, Christoph (Reader).
Subjects/Keywords: Ultrafast Molecular Dynamics
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APA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bao, J. (2011). Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:11189/
Chicago Manual of Style (16th Edition):
Bao, Jie. “Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems.” 2011. Doctoral Dissertation, Brown University. Accessed March 06, 2021.
https://repository.library.brown.edu/studio/item/bdr:11189/.
MLA Handbook (7th Edition):
Bao, Jie. “Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems.” 2011. Web. 06 Mar 2021.
Vancouver:
Bao J. Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems. [Internet] [Doctoral dissertation]. Brown University; 2011. [cited 2021 Mar 06].
Available from: https://repository.library.brown.edu/studio/item/bdr:11189/.
Council of Science Editors:
Bao J. Ultrafast Photoelectron Spectroscopy and Mass Spectrometry
as Probes for Structural Dynamics of Highly Excited Large Molecular
Systems. [Doctoral Dissertation]. Brown University; 2011. Available from: https://repository.library.brown.edu/studio/item/bdr:11189/
Colorado State University
8.
Tracy, Kathryn Marie.
Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy.
Degree: PhD, Chemistry, 2018, Colorado State University
URL: http://hdl.handle.net/10217/191357
► 2D IR spectroscopy is a nonlinear optical method with the ability to characterize condensed phase chemical systems. It offers information regarding structure and dynamics of…
(more)
▼ 2D IR spectroscopy is a nonlinear optical method with the ability to characterize condensed phase chemical systems. It offers information regarding structure and dynamics of chemical systems. Recent efforts have been made to resolve spatially the molecular structure and dynamics of heterogeneous samples, which shows the feasibility of
ultrafast 2D IR microscopy. To image more efficiently, we have moved away from the Ti:sapphire based laser systems and OPA systems that operate at one to several kHz typically used in 2D IR spectroscopy. Instead, for the first time we have demonstrated higher repetition rate, 2D IR spectroscopy at 100 kHz. Achieving this higher repetition rate was accomplished by utilizing advances in diode pumped ytterbium oscillators and amplifiers, and is based on an OPCPA utilizing Mg:PPLN followed by DFG in ZGP. Using this system, we have for the first time, demonstrated the interfacing of IR compatible microfluidics with 2D IR spectroscopy to examine the solvatochromic pseudo-halide anion, cyanate in cosolvent environments. This high repetition rate source also provided a path to 2D IR microscopy experiments that explore the dynamics of complex, heterogeneous, chemical systems. We have shown the chemical dynamics in a room temperature ionic liquid microdroplet. Spatially resolved time-dependent 2D IR signals reveal three regions with different chemical dynamics—the bulk, the interface, and a region between the bulk and interface. This demonstration provides proof-of-concept to use 2D IR microscopy on a wide array of additional chemical systems.
Advisors/Committee Members: Krummel, Amber T. (advisor), Levinger, Nancy E. (committee member), Szamel, Grzegorz (committee member), Krueger, David A. (committee member), Fisk, John D. (committee member).
Subjects/Keywords: ultrafast dynamics; ultrafast spectroscopy; OPCPA; 2D IR microscopy; ultrafast lasers; 2D IR spectroscopy
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Manager
APA (6th Edition):
Tracy, K. M. (2018). Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/191357
Chicago Manual of Style (16th Edition):
Tracy, Kathryn Marie. “Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy.” 2018. Doctoral Dissertation, Colorado State University. Accessed March 06, 2021.
http://hdl.handle.net/10217/191357.
MLA Handbook (7th Edition):
Tracy, Kathryn Marie. “Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy.” 2018. Web. 06 Mar 2021.
Vancouver:
Tracy KM. Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy. [Internet] [Doctoral dissertation]. Colorado State University; 2018. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/10217/191357.
Council of Science Editors:
Tracy KM. Visualizing dynamics using 100 kHz 2D IR spectroscopy and microscopy. [Doctoral Dissertation]. Colorado State University; 2018. Available from: http://hdl.handle.net/10217/191357
University of California – Berkeley
9.
Schlau-Cohen, Gabriela Sadira.
Multidimensional Spectroscopy of Photosynthetic Complexes.
Degree: Chemistry, 2011, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/5j97q5cw
► Experiments using two-dimensional (2D) electronic spectroscopy to investigate the structure-function relationships that give rise to photosynthetic energy transfer within pigment protein complexes are presented and…
(more)
▼ Experiments using two-dimensional (2D) electronic spectroscopy to investigate the structure-function relationships that give rise to photosynthetic energy transfer within pigment protein complexes are presented and discussed in this dissertation. 2D electronic spectroscopy using ultrafast laser pulses throughout the visible regime was applied to study excitation energy transfer in the major light harvesting complex of photosystem II (LHCII) and the reaction center from purple bacteria. These experiments elucidated information about the excited state structure and the energy transfer timescales within these complexes. All-parallel 2D spectroscopy was used to monitor the energy transfer dynamics in LHCII and reveals previously unobserved sub-100 fs energy transfer between the chlorophyll-b (Chl-b) and chlorophyll-a (Chl-a) bands and within the Chl-a band. Reproducing these results with simulations led to improvements in the values of the uncoupled transition energies of the chlorophyll in the working Hamiltonian of LHCII. The delocalized excited states observed in the experimental and theoretical results were found to increase the range of optimal angles for energy transfer from LHCII to neighboring pigment-protein complexes, as opposed to the case of a single, isolated donor excited state. Polarized 2D spectroscopy experiments reported here identified previously unresolved excitation energy transfer steps in LHCII. These results were used to determine the angle betweentransition dipole moments of the donor and acceptor. A new method was developed to use the angle between transition dipole moments to find the uncoupled transition energies of the chlorophyll, previously the major unknown for an accurate electronic Hamiltonian. This method was applied to LHCII. Quantum coherence, or a long-lived superposition of excited states, was observed in LHCII using a second polarization sequence. The observable timescales of coherence was determined to be 700-900 fs, which illustrates that quantum coherence lasts longer than many energy transfer steps. The potential contribution of coherence to the robustness of photosynthetic energy transfer to the rugged energy landscape and to temperature variations is discussed. Experiments on the B band of the bacterial reaction center were able to isolate the previously inseparable two peaks and observe energy transfer between these two excited states. A new extension of 2D spectroscopy, two-color 2D spectroscopy, was demonstrated forexamining the interactions between two spectrally separate chromophores. Using this approach, energy was found to transfer from the carotenoid to the bacteriochlorophyll both via S1 and via Qx in the bacterial reaction center in an approximately 2:1 ratio, and within about 750 fs.
Subjects/Keywords: Physical chemistry; Photosynthesis; Spectroscopy; Ultrafast
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APA (6th Edition):
Schlau-Cohen, G. S. (2011). Multidimensional Spectroscopy of Photosynthetic Complexes. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/5j97q5cw
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Schlau-Cohen, Gabriela Sadira. “Multidimensional Spectroscopy of Photosynthetic Complexes.” 2011. Thesis, University of California – Berkeley. Accessed March 06, 2021.
http://www.escholarship.org/uc/item/5j97q5cw.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Schlau-Cohen, Gabriela Sadira. “Multidimensional Spectroscopy of Photosynthetic Complexes.” 2011. Web. 06 Mar 2021.
Vancouver:
Schlau-Cohen GS. Multidimensional Spectroscopy of Photosynthetic Complexes. [Internet] [Thesis]. University of California – Berkeley; 2011. [cited 2021 Mar 06].
Available from: http://www.escholarship.org/uc/item/5j97q5cw.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Schlau-Cohen GS. Multidimensional Spectroscopy of Photosynthetic Complexes. [Thesis]. University of California – Berkeley; 2011. Available from: http://www.escholarship.org/uc/item/5j97q5cw
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Cornell University
10.
Bucklew, Victor.
Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators.
Degree: PhD, Electrical Engineering, 2014, Cornell University
URL: http://hdl.handle.net/1813/38937
► This work formulates, theorizes, and presents a novel method of modelocking ultrafast sources with short gain media. By appropriately balancing the complex interplay of elements…
(more)
▼ This work formulates, theorizes, and presents a novel method of modelocking
ultrafast sources with short gain media. By appropriately balancing the complex interplay of elements within the laser cavity, a passive self-similar pulse solution can be obtained which can support one to two orders of magnitude more energy than other pulse evolutions in an analogous system before encountering wave-breaking. A purely analytical model which describes this pulse evolution is presented, and the results are shown to match simulation and explain the connection between this evolution in the solid state, and the analogue evolution in fiber laser systems. Several methods for realizing this pulse evolution experimentally are detailed and shown to be feasible through numerical simulation. Additionally, theoretical and numerical work is presented which describe a self similar evolution in passive fiber with increasing nonlinearity. Lastly, numerical experiments are presented which detail the feasibility of a nonlinear-dispersive self similar evolution in a fiber laser.
Advisors/Committee Members: Pollock, Clifford Raymond (chair), Lipson, Michal (committee member), Wise, Frank William (committee member).
Subjects/Keywords: Ultrafast; Laser; Self-similar
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APA (6th Edition):
Bucklew, V. (2014). Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/38937
Chicago Manual of Style (16th Edition):
Bucklew, Victor. “Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators.” 2014. Doctoral Dissertation, Cornell University. Accessed March 06, 2021.
http://hdl.handle.net/1813/38937.
MLA Handbook (7th Edition):
Bucklew, Victor. “Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators.” 2014. Web. 06 Mar 2021.
Vancouver:
Bucklew V. Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators. [Internet] [Doctoral dissertation]. Cornell University; 2014. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1813/38937.
Council of Science Editors:
Bucklew V. Self-Similar Evolution Of Ultrafast Pulses In Solid-State Laser Resonators. [Doctoral Dissertation]. Cornell University; 2014. Available from: http://hdl.handle.net/1813/38937
University of Michigan
11.
Abere, Michael J.
From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures.
Degree: PhD, Materials Science and Engineering, 2015, University of Michigan
URL: http://hdl.handle.net/2027.42/116658
► The interaction between multiple intense ultrashort laser pulses and solids universally produces a regular surface corrugation. We have identified a coupled mechanism that operates in…
(more)
▼ The interaction between multiple intense ultrashort laser pulses and solids universally produces a regular surface corrugation. We have identified a coupled mechanism that operates in a specific range of fluences in semiconductors between the band-gap collapse and
ultrafast-melt thresholds that produces a unique corrugation known as high spatial frequency laser induced periodic surface structures (HSFL). The structures have period < 0.3 times the laser wavelength and are predominately epitaxial single crystal. HSFL formation is initiated when the intense laser field softens the interatomic binding potential, which leads to an
ultrafast generation of point defects. The interplay between surface plasmon polaritons and transient surface morphologies driven by strain relaxation, via diffusing defects, localizes the point defect generation, which results in the evolution and eventual completion of HSFL formation. Changing the material and laser wavelength dependent surface plasmon polariton response allows for either control over the HSFL period or complete inhibition of their formation. Control over the HSFL formation mechanism opens the potential for
ultrafast laser directed self-assembly.
Advisors/Committee Members: Yalisove, Steven M. (committee member), Phillips, Jamie Dean (committee member), Millunchick, Joanna Mirecki (committee member), Halloran, John W (committee member), Torralva, Ben R. (committee member).
Subjects/Keywords: Ultrafast Laser; Physics; Science
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APA (6th Edition):
Abere, M. J. (2015). From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/116658
Chicago Manual of Style (16th Edition):
Abere, Michael J. “From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures.” 2015. Doctoral Dissertation, University of Michigan. Accessed March 06, 2021.
http://hdl.handle.net/2027.42/116658.
MLA Handbook (7th Edition):
Abere, Michael J. “From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures.” 2015. Web. 06 Mar 2021.
Vancouver:
Abere MJ. From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures. [Internet] [Doctoral dissertation]. University of Michigan; 2015. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2027.42/116658.
Council of Science Editors:
Abere MJ. From Point Defects to Ripples: Ultrafast Laser Induced High Spatial Frequency Laser Induced Periodic Surface Structures. [Doctoral Dissertation]. University of Michigan; 2015. Available from: http://hdl.handle.net/2027.42/116658
McMaster University
12.
Aljekhedab, Fahad.
Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers.
Degree: PhD, 2019, McMaster University
URL: http://hdl.handle.net/11375/23903
► The mechanical tools currently used in orthopedic and dental surgery are imprecise and may cause heat damage. Ultrashort pulse lasers are a promising replacement, but…
(more)
▼ The mechanical tools currently used in orthopedic and dental surgery are imprecise and may cause heat damage. Ultrashort pulse lasers are a promising replacement, but their ablation efficiency must be improved. The goal of this thesis was to achieve high ablation efficiency, precision, and minimal collateral damage using an ultrafast laser on bovine hard tissue. This work used two types of lasers: a Ti:Sapphire laser (210 fs, 800 nm, 1 kHz) and a fiber laser (1 ps, 1035 nm, 100 kHz - 1 MHz).
This thesis begins with a review of the literature on laser-tissue interactions and the effect of certain laser parameters on the ablation process. The next section uses a Ti:Sapphire laser and bovine bone to explore the properties of laser-tissue interactions, including ablation threshold and incubation coefficient. Results showed that as the number of incident pulses goes up, ablation threshold goes down. The threshold range went from 1.08 ± 0.15 J/cm2 at 25 incident pulses to 0.73 ± 0.12 J/cm2 at 1000 pulses. The incubation coefficient, S, was calculated to be 0.90 ± 0.02.
The relationship between ablation depth and fluence, scanning speed, and number of successive passes was characterized as a first step towards preparing large-cavity with high removal efficiency using a Ti:Sapphire and fiber lasers. Depth increased with fluence and number of passes, but it decreased with scanning speed.
The influence of environmental conditions including air, compressed air flow, still water and flowing water on cavity ablation depth, and rate was investigated using a Ti:Sapphire laser with aim to enhance ablation efficiency. Findings showed that the deepest cavities and fastest ablation rates were achieved with compressed air flow. Air flow also resulted in the most precise cuts, the smoothest surfaces, and the absence of microcracks. This thesis also used a fiber laser to explore the effect of fluence and repetition rate on removal rate and ablation quality. Results indicated that ablation rate increases with fluence and pulse rate. When the repetition rate exceeded 600 kHz, the laser caused thermal and mechanical damage, indicated by the presence of amorphous carbon. The effect of environmental conditions and laser parameters such as repetition rate provide valuable insights into the ultrafast laser ablation mechanisms for medicine and biology field.
Thesis
Doctor of Philosophy (PhD)
Advisors/Committee Members: Fang, Qiyin, Haugen, Harold, Wohl, Greg, Biomedical Engineering.
Subjects/Keywords: Ultrafast pulsed laser ablation
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APA (6th Edition):
Aljekhedab, F. (2019). Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/23903
Chicago Manual of Style (16th Edition):
Aljekhedab, Fahad. “Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers.” 2019. Doctoral Dissertation, McMaster University. Accessed March 06, 2021.
http://hdl.handle.net/11375/23903.
MLA Handbook (7th Edition):
Aljekhedab, Fahad. “Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers.” 2019. Web. 06 Mar 2021.
Vancouver:
Aljekhedab F. Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers. [Internet] [Doctoral dissertation]. McMaster University; 2019. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11375/23903.
Council of Science Editors:
Aljekhedab F. Enhancement of Cortical Bone Ablation Using Ultrafast Pulsed Lasers. [Doctoral Dissertation]. McMaster University; 2019. Available from: http://hdl.handle.net/11375/23903
University of Wollongong
13.
Hargreaves, Rhys.
Ultrafast demagnetisation as a Terahertz
source.
Degree: MS–
Research, 2014, University of Wollongong
URL: ;
https://ro.uow.edu.au/theses/4274
► Ultrafast demagnetisation of ferromagnets by ultrafast laser pulses provides a unique window for the investigation of spin dynamics in ferromagnets. Ultrafast demagnetisation has previously…
(more)
▼ Ultrafast
demagnetisation of ferromagnets by ultrafast laser pulses
provides a unique window for the investigation of spin
dynamics in ferromagnets. Ultrafast demagnetisation has
previously been observed via the generation of Terahertz
emissions (among other methods) using amplified lasers,
and by magneto-optical methods using non-amplified
lasers. Using a fast (short pulse length), low power
laser, with lower pulse energies, but comparable peak
pulse power density, models of ultrafast demagnetisation
were compared. The models compared
were the Two Temperature model proposed by Vaterlaus et
al.[1], the Three Temperature Model by Beaurepaire et
al.[2], the Non- Thermal-Electron model by Ju et al.[3],
and the Microscopic Three Temperature Model by Koopmans
et al.[4]. A quasi-null result of THz spectral power
density < 10−22 W ·
THz−1, from Nickel samples, was
inconsistent with predictions of the Two Temperature
Model. More accurate measurements of Terahertz emission
were not possible due to cumulative noise effects from
the high pulse repetition frequency, and low pulse energy
used. In addition, theoretical
investigations into the Microscopic Three Temperature
Model were undertaken. These predicted that the peak
Terahertz emission frequency is inversely proportional to
the ultrafast pulse length. It was also predicted that
(for the laser modelled) peak power output is achieved by
initiating demagnetisation from ≈80% of the Curie
temperature of the material, and that this result is
approximately independent of the
material.
Subjects/Keywords: Terahertz; ultrafast; spin dynamics; magnetism
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APA (6th Edition):
Hargreaves, R. (2014). Ultrafast demagnetisation as a Terahertz
source. (Masters Thesis). University of Wollongong. Retrieved from ; https://ro.uow.edu.au/theses/4274
Chicago Manual of Style (16th Edition):
Hargreaves, Rhys. “Ultrafast demagnetisation as a Terahertz
source.” 2014. Masters Thesis, University of Wollongong. Accessed March 06, 2021.
; https://ro.uow.edu.au/theses/4274.
MLA Handbook (7th Edition):
Hargreaves, Rhys. “Ultrafast demagnetisation as a Terahertz
source.” 2014. Web. 06 Mar 2021.
Vancouver:
Hargreaves R. Ultrafast demagnetisation as a Terahertz
source. [Internet] [Masters thesis]. University of Wollongong; 2014. [cited 2021 Mar 06].
Available from: ; https://ro.uow.edu.au/theses/4274.
Council of Science Editors:
Hargreaves R. Ultrafast demagnetisation as a Terahertz
source. [Masters Thesis]. University of Wollongong; 2014. Available from: ; https://ro.uow.edu.au/theses/4274
University of Kansas
14.
Werake, Lalani Kumari.
BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES.
Degree: PhD, Physics & Astronomy, 2011, University of Kansas
URL: http://hdl.handle.net/1808/8400
► Abstract Exploring the spin degree of freedom of electrons has been recognized as a promising solution to several limitations in semiconductor device industry. Injection, transport,…
(more)
▼ Abstract Exploring the spin degree of freedom of electrons has been recognized as a promising solution to several limitations in semiconductor device industry. Injection, transport, detection and manipulation of "spin" in materials are the key elements of this new electronic technology, known as spintronics. Despite the extensive efforts in recent years, there are still significant challenges and spintronics is still in the research phase. This dissertation is devoted to study one of these key processes: spin transport. We used quantum interference and control technique to inject spin currents. Two techniques are developed to detect the spin transport, namely a pump probe technique and a second-harmonic generation technique. Spin transport in several materials and structures are studied, including GaAs bulk, quantum wells, and germanium wafers. We observed the intrinsic inverse spin-Hall effect by time-resolving the ballistic spin and charge transport. We found that the Hall current appeared before the first scattering event. We discovered a new nonlinear optical effect, second-harmonic generation, induced by the pure spin current, and demonstrated that it can be used to directly detect pure spin currents. We have also discovered a charge-current-induced second-harmonic generation process, and used it to study plasma oscillation in GaAs. Finally, we also attempted to observe the second harmonic generation induced by spin polarized and spin unpolarized carrier populations. We did not observe a significant change in the observed second harmonic generation induced by spin polarized and spin unpolarized carrier populations.
Advisors/Committee Members: Zhao, Hui (advisor), Zhao, Hui (cmtemember), Han, Siyuan (cmtemember), Wu, Judy (cmtemember), Antonik, Matthew (cmtemember), Elles, Christopher (cmtemember).
Subjects/Keywords: Physics; Semiconductor; Spintronics; Ultrafast lasers
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APA (6th Edition):
Werake, L. K. (2011). BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES. (Doctoral Dissertation). University of Kansas. Retrieved from http://hdl.handle.net/1808/8400
Chicago Manual of Style (16th Edition):
Werake, Lalani Kumari. “BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES.” 2011. Doctoral Dissertation, University of Kansas. Accessed March 06, 2021.
http://hdl.handle.net/1808/8400.
MLA Handbook (7th Edition):
Werake, Lalani Kumari. “BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES.” 2011. Web. 06 Mar 2021.
Vancouver:
Werake LK. BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES. [Internet] [Doctoral dissertation]. University of Kansas; 2011. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1808/8400.
Council of Science Editors:
Werake LK. BALLISTIC CARRIER TRANSPORT IN SEMICONDUCTORS STUDIED BY ULTRAFAST LASER TECHNIQUES. [Doctoral Dissertation]. University of Kansas; 2011. Available from: http://hdl.handle.net/1808/8400
University of Exeter
15.
Hale, Peter John.
Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene.
Degree: PhD, 2012, University of Exeter
URL: https://ore.exeter.ac.uk/repository/handle/10036/3600
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578992
► In this thesis the nonlinear and nonequilibrium properties of graphene are experimentally investigated using degenerate four – wave mixing and time – resolved pump – probe spectroscopy. High…
(more)
▼ In this thesis the nonlinear and nonequilibrium properties of graphene are experimentally investigated using degenerate four – wave mixing and time – resolved pump – probe spectroscopy. High quality exfoliated natural graphite and large area epitaxial graphene on silicon carbide are investigated with femtosecond and picosecond ultrafast pulses in the near – infrared. A bespoke technique for suspending exfoliated graphene is also presented. In Chapter 3, the third – order nonlinear susceptibility of graphene is measured for the first time and shows a remarkably large response. Degenerate four – wave mixing at near – infrared wavelengths demonstrates an almost dispersionless emission over a broad spectral range. Quantum kinetic theory is employed to estimate the magnitude of the response and is in good agreement with the experimental data. The large susceptibility enables high contrast imaging, with a monolayer flake contrast of the order 107 times higher than for standard reflection imaging. The degenerate four – wave mixing technique is utilised in Chapter 4 to measure the interface carbon signal of epitaxially grown graphene on silicon carbide. Comparable third – order signal from the silicon carbide bulk prevents true interface imaging. Excluding the third – order emission from detection by elongating the emission to outside a band – pass filter range allows for pure interfacial luminescence imaging. Features within the two growth faces are investigated with Raman spectroscopy. Nonlinear measurements are an increasingly popular tool for investigating fundamental properties of graphene. Chapter 5 investigates the influence of ultrafast pulses on the nonlinear response of graphene. High instantaneous intensities at the sample are shown to reduce the nonlinear emission by a factor or two. Comparing the Raman peak positions, widths and intensities before and after irradiation points to a huge doping of the samples, of the order 500 meV. In Chapter 6 the relaxation of photoexcited carriers is measured via time – resolved pump – probe spectroscopy, where a layer dependence of hot phonon decay is observed. Single layer flakes are observed to relax faster than bilayers and trilayers, with an asymptote reached at approximately four layers. Removing the substrate and measuring fully suspended samples reveals the same trend, suggesting that substrate interactions are not the cause of the enhanced decay. The decay mechanism is therefore intrinsic to graphene, perhaps due to coupling to out – of – plane, flexural phonons. The thickness dependence of epitaxial graphene on silicon carbide is compared to that of exfoliated flakes where the layer dependence is not observed. Phonon relaxation times, however, are in good agreement. Predictions for future investigations into this novel material based on the works here are suggested in Chapter 7. Preliminary pump – probe measurements at high carrier concentrations are an example of such progress, which will offer an insight into further decay mechanisms in graphene.
Subjects/Keywords: 546.681; graphene; ultrafast; nonlinear; nonequilibrium
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APA (6th Edition):
Hale, P. J. (2012). Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene. (Doctoral Dissertation). University of Exeter. Retrieved from https://ore.exeter.ac.uk/repository/handle/10036/3600 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578992
Chicago Manual of Style (16th Edition):
Hale, Peter John. “Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene.” 2012. Doctoral Dissertation, University of Exeter. Accessed March 06, 2021.
https://ore.exeter.ac.uk/repository/handle/10036/3600 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578992.
MLA Handbook (7th Edition):
Hale, Peter John. “Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene.” 2012. Web. 06 Mar 2021.
Vancouver:
Hale PJ. Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene. [Internet] [Doctoral dissertation]. University of Exeter; 2012. [cited 2021 Mar 06].
Available from: https://ore.exeter.ac.uk/repository/handle/10036/3600 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578992.
Council of Science Editors:
Hale PJ. Illuminating flatland : nonlinear and nonequilibrium optical properties of graphene. [Doctoral Dissertation]. University of Exeter; 2012. Available from: https://ore.exeter.ac.uk/repository/handle/10036/3600 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.578992
Rice University
16.
Anthonio, Bryan.
Ultrafast Spectroscopy of (6,5) Carbon Nanotubes.
Degree: MS, Natural Sciences, 2020, Rice University
URL: http://hdl.handle.net/1911/107989
► Single-wall carbon nanotubes (SWCNTs) represent an exemplary model system for studying one-dimensional (1-D) physics in condensed matter research. Conceptually, they can be presented as a…
(more)
▼ Single-wall carbon nanotubes (SWCNTs) represent an exemplary model system for studying one-dimensional (1-D) physics in condensed matter research. Conceptually, they can be presented as a rolled-up sheet of graphene, and depending on their crystal structure they either exhibit properties of semiconductors or metals. These materials also feature strong Coulomb interactions that have profound effects, giving rise to optical properties which differ from those of 2-D and 3-D materials. Chief amongst these properties is the tendency for optical excitations to only generate bound electron-hole pairs in SWCNTs, known as excitons, rather than free electron-hole pairs. In this thesis, we used
ultrafast optical pump-probe spectroscopy to investigate both coherent and noncoherent phenomena in (6,5) SWCNTs. The samples used for this investigation included two different ensembles of individually-suspended (6,5)-enriched SWCNTs in solution. In one ensemble, the SWCNTs were suspended in an aqueous solution containing surfactants, whereas the SWCNTs in the other ensemble were suspended using an aromatic polymer in a toluene solution. In this study, we observed a coherent blueshift of the lowest-lying exciton resonance when the SWCNTs were photoexcited below the band gap, a signature of the optical Stark effect. When photoexciting the samples at the second-highest exciton resonance, we observed quenching of the lowest exciton resonance for the SWCNTs in the aqueous suspension but not for those that were suspended in toluene. This observation alone raises further questions regarding how different dielectric environments affect the carrier dynamics of SWCNTs.
Advisors/Committee Members: Kono, Junichiro (advisor).
Subjects/Keywords: optics; carbon nanotubes; spectroscopy; ultrafast
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APA (6th Edition):
Anthonio, B. (2020). Ultrafast Spectroscopy of (6,5) Carbon Nanotubes. (Masters Thesis). Rice University. Retrieved from http://hdl.handle.net/1911/107989
Chicago Manual of Style (16th Edition):
Anthonio, Bryan. “Ultrafast Spectroscopy of (6,5) Carbon Nanotubes.” 2020. Masters Thesis, Rice University. Accessed March 06, 2021.
http://hdl.handle.net/1911/107989.
MLA Handbook (7th Edition):
Anthonio, Bryan. “Ultrafast Spectroscopy of (6,5) Carbon Nanotubes.” 2020. Web. 06 Mar 2021.
Vancouver:
Anthonio B. Ultrafast Spectroscopy of (6,5) Carbon Nanotubes. [Internet] [Masters thesis]. Rice University; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1911/107989.
Council of Science Editors:
Anthonio B. Ultrafast Spectroscopy of (6,5) Carbon Nanotubes. [Masters Thesis]. Rice University; 2020. Available from: http://hdl.handle.net/1911/107989
17.
Li, Jiebo.
Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy.
Degree: PhD, Natural Sciences, 2014, Rice University
URL: http://hdl.handle.net/1911/88085
► The methodology of ultrafast multiple-mode multiple-dimensional vibrational spectroscopy has been developed and applied to investigate the vibrational energy dissipation in condensed phase. In particular, experiments…
(more)
▼ The methodology of
ultrafast multiple-mode multiple-dimensional vibrational spectroscopy has been developed and applied to investigate the vibrational energy dissipation in condensed phase. In particular, experiments have been focused on the studies of vibrational energy relaxation and mode-specific vibrational energy transfer in both heterogeneous and homogeneous phases.
This thesis presents two distinctive vibrational energy dissipation pathways for molecules absorbed on the typical heterogeneous metal nanoparticle surfaces. On 2-10 nm platinum and palladium nanoparticles, it was found that the electronic excitation-mediated vibrational energy dissipation (~2ps) was at least one order magnitude faster than direct vibration-vibration relaxation (50ps). This electronic energy damping is accompanied by low frequency thermal energy generation on metallic surfaces. This electronic mediated pathway dominates until the electronic property of the particle is altered by reducing size to ~1nm. The energy relaxation pathway also could be altered by changing the chemical nature of the metallic nanoparticle. These findings are of fundamental importance to ultimately understanding the nature of heterogeneous catalysis.
This thesis also demonstrates mode-specific vibrational energy exchange between ions in electrolyte solution. (i) Interactions between model molecules representing different building-blocks of proteins and thiocyanate anions in aqueous solutions are studied. The binding affinity between the thiocyanate anions and the charged amino acid residues is about 20 times bigger than that between water molecules and the amino acids, and about 5~10 times larger than that between the anions and neutral backbone amide groups. (ii) Ion segregation was also investigated by mode-specific vibrational energy exchange between thiocyanate anions. In aqueous solutions, it was found that “structure maker” ions, such as F-, would stay in the “water phase” and thereby promote aggregation of the SCN- in an “ionic phase”. “Structure breaker” ions, such as I-, would break the ionic SCN- phase. (iii) Mediated by combination band, vibrational energy flow down from thiocyanate to ammonium was used to confirm that ion pair is formed between ammonium and thiocyanate in aqueous solutions. Investigations of these microscopic structures and dynamics of aqueous salt solutions experiments will add depth to our understanding of general macroscopic properties of electrolyte solutions.
Advisors/Committee Members: Zheng, Junrong (advisor), Kolomeisky, Anatoly B. (committee member), Kono, Junichiro (committee member).
Subjects/Keywords: Energy transfer; Ultrafast Infrared Spectroscopy
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APA (6th Edition):
Li, J. (2014). Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/88085
Chicago Manual of Style (16th Edition):
Li, Jiebo. “Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy.” 2014. Doctoral Dissertation, Rice University. Accessed March 06, 2021.
http://hdl.handle.net/1911/88085.
MLA Handbook (7th Edition):
Li, Jiebo. “Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy.” 2014. Web. 06 Mar 2021.
Vancouver:
Li J. Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy. [Internet] [Doctoral dissertation]. Rice University; 2014. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1911/88085.
Council of Science Editors:
Li J. Vibrational Energy Dissipation in Condensed Phases Investigated by Multiple Modes Multiple Dimensional Vibrational Spectroscopy. [Doctoral Dissertation]. Rice University; 2014. Available from: http://hdl.handle.net/1911/88085
Rice University
18.
Wen, Xiewen.
Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies.
Degree: PhD, Engineering, 2017, Rice University
URL: http://hdl.handle.net/1911/105469
► In the past decade, inspired by the discovery and of graphene, two dimensional (2D) materials which only consist of a single layer of atoms have…
(more)
▼ In the past decade, inspired by the discovery and of graphene, two dimensional (2D) materials which only consist of a single layer of atoms have attracted attention of scientists. A series of 2D materials including semiconducting transition metal dichalcogenides, black Phosphors, Silicene, insulating h-BN, and a number of metallic and semi-metallic materials have been synthesized and studied. Many novel physical phenomena and unique applications have been explored. Based on the rich 2D materials library, in recent years, a new sort of materials – Van der Waals (VDW) heterostructure has been created and investigated, unlike conventional semiconductor heterostructures, VDW Heterostructures do not require lattice matching and complicated growth, and they rely on VDW forces between 2D materials so they can be fabricated via artificial stacking, however they can exhibit great deal of phenomena and applications which conventional heterostructures can or cannot realize. Now people tend to believe band structures of individual layers experienced none to slight change in the VDW Heterostructures, so the charge transfers between layers become the crucial factors determining the properties of the VDW Heterostructures. Microscopies, electronics and spectroscopies are main means of studying interlayer interactions, in this thesis, we creatively utilized microscopic optical pump, mid-IR probe
ultrafast spectroscopies to reveal the charge transfer dynamics of several VDW Heterostructure systems with different band alignments, include MoS2/WS2, MoS2/MoSe2, MoSe2/Graphene, MoS2/MoSe2/Graphene with different stacking orders, and we observed the charge transfer dynamics and the formation and extinction of interlayer excitons in VDW Heterostructures, a series of novel physical phenomena have been discovered experimentally. And by studying plasmonics-2D material and VDW Heterostructures systems, hot electron injection pathways were clearly revealed for the first time. The work in this thesis not only clarify some controversial opinions of the newly emerging VDW Heterostructures fields but also provide significant experimental evidence for future research.
Advisors/Committee Members: Lou, Jun (advisor), Ajayan, Pulickel (committee member).
Subjects/Keywords: 2D materials; graphene; spectroscopies; ultrafast
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APA (6th Edition):
Wen, X. (2017). Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/105469
Chicago Manual of Style (16th Edition):
Wen, Xiewen. “Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies.” 2017. Doctoral Dissertation, Rice University. Accessed March 06, 2021.
http://hdl.handle.net/1911/105469.
MLA Handbook (7th Edition):
Wen, Xiewen. “Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies.” 2017. Web. 06 Mar 2021.
Vancouver:
Wen X. Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies. [Internet] [Doctoral dissertation]. Rice University; 2017. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1911/105469.
Council of Science Editors:
Wen X. Carrier transfer dynamics between atomic layers in Van Der-Waals heterostructures probed by ultrafast spectroscopies. [Doctoral Dissertation]. Rice University; 2017. Available from: http://hdl.handle.net/1911/105469
Rice University
19.
Cong, Kankan.
Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes.
Degree: PhD, Natural Sciences, 2018, Rice University
URL: http://hdl.handle.net/1911/105639
► Single-wall carbon nanotubes (SWCNTs) are unique one-dimensional (1D) condensed matter systems in which strongly enhanced Coulomb interactions are combined with unusual band structure. There are…
(more)
▼ Single-wall carbon nanotubes (SWCNTs) are unique one-dimensional (1D) condensed matter systems in which strongly enhanced Coulomb interactions are combined with unusual band structure. There are metallic and semiconducting SWCNTs, in both of which electron-electron interactions have significant impact on their electronic and optical properties. In this dissertation work, we used
ultrafast optical pump-probe spectroscopy to investigate nonequilibrium dynamics of photogenerated electron-hole pairs, or excitons, in a sample in which a particular species, or chirality, of semiconducting SWCNTs was enriched. Specifically, we studied both an aqueous suspension and an aligned film of (6,5) SWCNTs. Depending on the pump photon energy, intensity, and polarization, different physical processes ensue after
ultrafast pumping, including coherent light-matter interactions and incoherent relaxation of carriers/excitons. For example, under below-gap pumping, a transient blueshift of the exciton peak occurred, only during the pump pulse duration, a hallmark of the optical Stark effect. Under resonant pumping, transient splitting of the exciton peak was observed within the pulse duration, which is a manifestation of the Rabi doublet due to coherent light-matter interaction in the strong coupling regime. The Rabi doublet was observed only under resonant or near-resonant pumping conditions. In the case of a macroscopically aligned (6,5) SWCNT film sample, an anisotropic Rabi doublet of the exciton peak was observed under resonant pumping. In the case of above-gap excitation, incoherent relaxation processes dominated the dynamics of excitons. Analysis of these
ultrafast, nonequilibrium, and strongly driven phenomena provided considerable new insight into the states and dynamics of electrons in the presence of extreme quantum confinement and strong many-body interactions.
Advisors/Committee Members: Kono, Junichiro (advisor).
Subjects/Keywords: Ultrafast optical spectroscopy; Carbon nanotubes
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APA (6th Edition):
Cong, K. (2018). Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/105639
Chicago Manual of Style (16th Edition):
Cong, Kankan. “Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes.” 2018. Doctoral Dissertation, Rice University. Accessed March 06, 2021.
http://hdl.handle.net/1911/105639.
MLA Handbook (7th Edition):
Cong, Kankan. “Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes.” 2018. Web. 06 Mar 2021.
Vancouver:
Cong K. Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes. [Internet] [Doctoral dissertation]. Rice University; 2018. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1911/105639.
Council of Science Editors:
Cong K. Coherent Light-Matter Coupling and Nonequilibrium Carrier Dynamics in Single-Chirality Carbon Nanotubes. [Doctoral Dissertation]. Rice University; 2018. Available from: http://hdl.handle.net/1911/105639
University of Minnesota
20.
Hinke, Jonathan Arthur.
Excited state dynamics of metalloporphyrins utilized in optoelectronic devices.
Degree: PhD, Chemical Physics, 2013, University of Minnesota
URL: http://purl.umn.edu/158327
► Energy consumption in the world is currently dominated by fossil fuels (85%) which include coal, gas, and oil while photovoltaics constitute a small portion (0.1%).…
(more)
▼ Energy consumption in the world is currently dominated by fossil fuels (85%) which include coal, gas, and oil while photovoltaics constitute a small portion (0.1%). The hotovoltaic market is primarily comprised of silicon based photovoltaics which are currently unable to compete with fossil fuels in cost per kilowatt hour. However, emerging organic photovoltaics (OPVs) have shown potential to be surpass silicon based photovoltaics and be cost competitive with fossil fuels. One of the limitations in OPVs is the short diffusion length (10 nm) relative to the absorbing layer thickness (100-200 nm). Porphyrins, of which chlorophylls are derivatives, remain at the forefront of OPV investigation due to their success in natural photosynthesis and potential in photovoltaic devices. Furthermore, platinum octaethyl porphyrin (PtOEP) has been estimated to have a diusion length between 18-30 nm and long triplet lifetime (100 microsecondss). This long diffusion length indicates that platinum porphyrins are able to efficiently funnel excitons to the interface, showing promise as suitable donor materials. Other porphyrins, such as nickel, palladium, tin, and indium show similar properties including strong absorption, enhanced excited state lifetimes, and charge separated states. This thesis investigates the excited state properties of porphyrin materials. Ultrafast pump probe spectroscopy allows for investigation of excited state dynamics including intramolecular energy transfer observed in nickel porphyrins. Femtosecond dynamics of palladium and platinum porphyrins are explored as well as triplet fusion in PtOEP neat films, providing a unique way to study energy transfer and amorphous films. Finally, pump probe studies aim to explain photoluminescent quenching behavior in tin and indium porphyrins through observation of charge separated states. Investigation of these
porphyrins is crucial to improving device efficiency through fundamental understanding of the excited state dynamics in films and neat films.
Subjects/Keywords: Dynamics; Excited; Porphyrin; Sectroscopy; Ultrafast
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APA (6th Edition):
Hinke, J. A. (2013). Excited state dynamics of metalloporphyrins utilized in optoelectronic devices. (Doctoral Dissertation). University of Minnesota. Retrieved from http://purl.umn.edu/158327
Chicago Manual of Style (16th Edition):
Hinke, Jonathan Arthur. “Excited state dynamics of metalloporphyrins utilized in optoelectronic devices.” 2013. Doctoral Dissertation, University of Minnesota. Accessed March 06, 2021.
http://purl.umn.edu/158327.
MLA Handbook (7th Edition):
Hinke, Jonathan Arthur. “Excited state dynamics of metalloporphyrins utilized in optoelectronic devices.” 2013. Web. 06 Mar 2021.
Vancouver:
Hinke JA. Excited state dynamics of metalloporphyrins utilized in optoelectronic devices. [Internet] [Doctoral dissertation]. University of Minnesota; 2013. [cited 2021 Mar 06].
Available from: http://purl.umn.edu/158327.
Council of Science Editors:
Hinke JA. Excited state dynamics of metalloporphyrins utilized in optoelectronic devices. [Doctoral Dissertation]. University of Minnesota; 2013. Available from: http://purl.umn.edu/158327
Georgia Tech
21.
Rhodes, Michelle Ann.
Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues.
Degree: PhD, Physics, 2016, Georgia Tech
URL: http://hdl.handle.net/1853/58132
► Theoretical limitations of several ultrashort pulse measurement techniques are investigated. Particular attention is paid to the consequences of averaging over many pulses of different shapes.…
(more)
▼ Theoretical limitations of several ultrashort pulse measurement techniques are investigated. Particular attention is paid to the consequences of averaging over many pulses of different shapes. Averaging over many pulses is a very common practice, and if the pulse shape varies then the measurement result will be incorrect. This issue, referred to as a coherent artifact, is simulated for frequency-resolved optical gating using several nonlinearities, spectral interferometry for direct electric field reconstruction, two-dimensional spectral shearing interferometry, self-referenced spectral interferometry using cross-polarized wave generation, and multiphoton intrapulse interference phase scan. The role of measurement feedback in identifying pulse-shape instability is explored where possible. Several techniques receive additional analysis, such as searching for ambiguities or simulating convergence conditions. In addition, a method for intuitively displaying spatiotemporally distorted pulses is explored and developed.
Advisors/Committee Members: Trebino, Rick (advisor), Curtis, Jennifer (committee member), Uzer, Turgay (committee member), Raman, Chandra (committee member), Perry, Joseph (committee member).
Subjects/Keywords: Ultrafast optics; Ultrashort pulse measurement
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APA ·
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APA (6th Edition):
Rhodes, M. A. (2016). Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/58132
Chicago Manual of Style (16th Edition):
Rhodes, Michelle Ann. “Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues.” 2016. Doctoral Dissertation, Georgia Tech. Accessed March 06, 2021.
http://hdl.handle.net/1853/58132.
MLA Handbook (7th Edition):
Rhodes, Michelle Ann. “Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues.” 2016. Web. 06 Mar 2021.
Vancouver:
Rhodes MA. Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues. [Internet] [Doctoral dissertation]. Georgia Tech; 2016. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1853/58132.
Council of Science Editors:
Rhodes MA. Troubleshooting ultrashort pulse measurement: the coherent artifact and other issues. [Doctoral Dissertation]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/58132
University of North Texas
22.
Mahat, Meg Bahadur.
Ultrafast Spectroscopy of Hybrid Ingan/gan Quantum Wells.
Degree: 2012, University of North Texas
URL: https://digital.library.unt.edu/ark:/67531/metadc149635/
► Group III nitrides are efficient light emitters. The modification of internal optoelectronic properties of these materials due to strain, external or internal electric field are…
(more)
▼ Group III nitrides are efficient light emitters. The modification of internal optoelectronic properties of these materials due to strain, external or internal electric field are an area of interest. Insertion of metal nanoparticles (MNPs) (Ag, Au etc) inside the V-shaped inverted hexagonal pits (IHP) of InGaN/GaN quantum wells (QWs) offers the potential of improving the light emission efficiencies. We have observed redshift and blueshift due to the Au MNPs and Ag MNPs respectively. This shift could be due to the electric field created by the MNPs through electrostatic image charge. We have studied the
ultrafast carrier dynamics of carriers in hybrid InGaN/GaN QWs. The change in quantum confinement stark effect due to MNPs plays an important role for slow and fast carrier dynamics. We have also observed the image charge effect on the
ultrafast differential transmission measurement due to the MNPs. We have studied the non-linear absorption spectroscopy of these materials. The QWs behave as a discharging of a nanocapacitor for the screening of the piezoelectric field due to the photo-excited carriers. We have separated out screening and excitonic bleaching components from the main differential absorption spectra of InGaN/GaN QWs.
Advisors/Committee Members: Neogi, Arup, Choi, Tae-Youl, Weathers, Duncan L., Philipose, Usha.
Subjects/Keywords: Ultrafast; semiconductor; quantum well
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University of Texas – Austin
23.
-8757-3113.
Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation.
Degree: PhD, Chemistry, 2019, University of Texas – Austin
URL: http://dx.doi.org/10.26153/tsw/2197
► Abstract: New nanostructured semiconductor materials such as nanocrystals and organic semiconductors constitute an attractive platform for optoelectronics design due to the ease of their processability…
(more)
▼ Abstract: New nanostructured semiconductor materials such as nanocrystals and organic semiconductors constitute an attractive platform for optoelectronics design due to the ease of their processability and highly tunable properties. Incorporating these new nanostructured materials into electrical circuits requires forming junctions between them and other layers in a device, yet the change in dielectric properties about these junctions can strongly perturb the electronic structure of the two layers. Specifically, the morphology of the interface between two materials greatly affect their ability to transfer charge and energy through the system, and the method through which this energy travels across a junction is poorly understood. To study these processes, an interfacial technique is required that measures the Density of States (Dos) at buried interfaces in working devices. In this thesis, we adapt an interface-selective optical technique, electronic sum frequency generation (ESFG), to study the dynamics of energy transfer across interfaces in these materials. We begin by developing “direct” detected ESFG to study the electronic states and morphology at the interface of thin films made from known organic semiconductor materials. Using direct ESFG, we examine the differences in the DoS at an interface in an organic thin film relative to its bulk. Through polarization optics, we study morphological changes in the film caused at the junction of the OSC and substrate. To account for interference from multiple ESFG active interfaces present in a thin film, we use a modeling system to separate contributions to the measured ESFG signal from the air exposed and buried interface of interest. We then adapt the direct detected ESFG to “heterodyne” detected ESFG (HD-ESFG), which significantly increases the detection ability of the ESFG spectrometer. Additionally, HD-ESFG allows us to measure the phase of the materials response, which direct ESFG cannot. This phase information can give a better understanding of the morphology at the interface and additional inputs for thin film interference modeling to better deconvolute the signal from the buried interface.
Advisors/Committee Members: Roberts, Sean T. (advisor), Baiz, Carls R (committee member), Vanden Bout, David A (committee member), Rose, Michael (committee member), Li, Xiaoqin (committee member).
Subjects/Keywords: Spectroscopy; Ultrafast; ESFG; Interfaces
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APA (6th Edition):
-8757-3113. (2019). Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://dx.doi.org/10.26153/tsw/2197
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Chicago Manual of Style (16th Edition):
-8757-3113. “Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation.” 2019. Doctoral Dissertation, University of Texas – Austin. Accessed March 06, 2021.
http://dx.doi.org/10.26153/tsw/2197.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
MLA Handbook (7th Edition):
-8757-3113. “Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation.” 2019. Web. 06 Mar 2021.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
-8757-3113. Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2019. [cited 2021 Mar 06].
Available from: http://dx.doi.org/10.26153/tsw/2197.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Council of Science Editors:
-8757-3113. Studying the Density of States of buried interfaces in organic semiconductor thin films using electronic sum frequency generation. [Doctoral Dissertation]. University of Texas – Austin; 2019. Available from: http://dx.doi.org/10.26153/tsw/2197
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
University of Cambridge
24.
Deacon, William.
Ultrafast Ultra-confined Plasmon Phonon Interactions.
Degree: PhD, 2019, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/316214
► The research contained within this thesis focuses on understanding and interrogating nanometrically confined ultrafast plasmon-phonon interactions. Nanometric plasmonic confinement is achieved by coupling the charge…
(more)
▼ The research contained within this thesis focuses on understanding and interrogating nanometrically confined ultrafast plasmon-phonon interactions. Nanometric plasmonic confinement is achieved by coupling the charge oscillations of a single gold nanoparticle to a gold substrate. This confines the plasmonic field to the single nanometre gap separating the two and is known as the NanoPar- ticle on Mirror (NPoM) structure. The first half of this thesis demonstrates the viability of using the coupling between confined plasmonic and acoustic modes as a sensitive nanomechanical probe. Initially this coupling allows us to discover the NPoM “bouncing mode” by performing ultrafast pump- probe spectroscopy on single constructs. Thorough finite element method simulations allow us to create a simple analytical model relat- ing the nanoparticle-substrate contact area to the bouncing mode period. This means that by measuring the bouncing mode period of a single NPoM structure we can calculate the size of the contact; a task impossible by any other means. The second half of this thesis is dedicated to furthering our under- standing of ultrafast molecular-phonon plasmon interactions. To fa- cilitate this we develop and utilise a fully automated time-resolved Coherent Anti-Stokes Raman Spectroscopy (tr-CARS) setup to mea- sure an acceleration of the vibrational decay of 2-mercaptopyridine within NPoM from 0 . 96 ps (determined from bulk Raman linewidth measurements) to far below 0 . 5 ps . To understand the origin of this acceleration we perform a series of power dependent Surface En- hanced Raman Spectroscopy (SERS) measurements on over 1000 NPoM constructs. We determine the acceleration to be most likely due to anharmonic phonon coupling driven by the high phonon pop- ulations induced by ultrafast pulses in plasmonic cavities. The power- series also reveals the presence of a previously unknown saturation effect due to intermolecular anharmonicity.
Subjects/Keywords: Physics; photonics; plasmonics; ultrafast; Raman
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APA (6th Edition):
Deacon, W. (2019). Ultrafast Ultra-confined Plasmon Phonon Interactions. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/316214
Chicago Manual of Style (16th Edition):
Deacon, William. “Ultrafast Ultra-confined Plasmon Phonon Interactions.” 2019. Doctoral Dissertation, University of Cambridge. Accessed March 06, 2021.
https://www.repository.cam.ac.uk/handle/1810/316214.
MLA Handbook (7th Edition):
Deacon, William. “Ultrafast Ultra-confined Plasmon Phonon Interactions.” 2019. Web. 06 Mar 2021.
Vancouver:
Deacon W. Ultrafast Ultra-confined Plasmon Phonon Interactions. [Internet] [Doctoral dissertation]. University of Cambridge; 2019. [cited 2021 Mar 06].
Available from: https://www.repository.cam.ac.uk/handle/1810/316214.
Council of Science Editors:
Deacon W. Ultrafast Ultra-confined Plasmon Phonon Interactions. [Doctoral Dissertation]. University of Cambridge; 2019. Available from: https://www.repository.cam.ac.uk/handle/1810/316214
Vanderbilt University
25.
-3410-7263.
Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.
Degree: PhD, Physics, 2020, Vanderbilt University
URL: http://hdl.handle.net/1803/16384
► In this dissertation we seek to present a comprehensive fluence and wavelength dependent ultrafast pump-probe transmission study of graphene supported on a soda-lime glass substrate…
(more)
▼ In this dissertation we seek to present a comprehensive fluence and wavelength dependent
ultrafast pump-probe transmission study of graphene supported on a soda-lime glass substrate for a range of pump fluences that enable us to observe both decreased and enhanced probe transmission regimes on a femtosecond timescale. Specifically, we study the crossover region from decreased to enhanced probe transmission, which occurs at an intermediate threshold pump fluence. At intermediate threshold pump fluences we observe an order of magnitude decrease in the relaxation time constant of the differential transmission as compared to higher and lower pump fluences. This optical effect can be explained by equal contributions of inter- and intraband transitions with opposite signs to the transient optical conductivity of graphene at intermediate pump fluences. Moreover, the intermediate threshold pump fluence is shown to increase with decreasing probe energy, which is in agreement with the theoretical model. Furthermore, we show that the relaxation time of the electronic temperature increases monotonically over the range of fluences studied. Comparison with the measured relaxation times of the differential transmission implies that pump fluence greatly modifies time-dependent optical properties, while the electron and phonon relaxation processes remain unaffected. In perspective, this work is of importance to graphene- based opto-electronic applications such as light modulators.
Advisors/Committee Members: Tolk, Norman H (advisor).
Subjects/Keywords: Ultrafast pump-probe dynamics; graphene
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APA (6th Edition):
-3410-7263. (2020). Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/16384
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Chicago Manual of Style (16th Edition):
-3410-7263. “Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.” 2020. Doctoral Dissertation, Vanderbilt University. Accessed March 06, 2021.
http://hdl.handle.net/1803/16384.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
MLA Handbook (7th Edition):
-3410-7263. “Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene.” 2020. Web. 06 Mar 2021.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
-3410-7263. Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. [Internet] [Doctoral dissertation]. Vanderbilt University; 2020. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/1803/16384.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Council of Science Editors:
-3410-7263. Ultrafast pump-probe fluence and wavelength dependent relaxation dynamics in graphene. [Doctoral Dissertation]. Vanderbilt University; 2020. Available from: http://hdl.handle.net/1803/16384
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
University of Minnesota
26.
Brooks, James.
Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry.
Degree: PhD, Chemistry, 2019, University of Minnesota
URL: http://hdl.handle.net/11299/217170
► The development of plasmonic nanostructures as light-activated photocatalysts has proven to be a promising research avenue due to their ability to access and drive unfavorable…
(more)
▼ The development of plasmonic nanostructures as light-activated photocatalysts has proven to be a promising research avenue due to their ability to access and drive unfavorable chemical reactions. Theses chemical reactions are fueled by the presence of surface plasmons, which are the collective oscillation of the free electron density on the material’s surface. Once a surface plasmon is photoexcited, their initial energy rapidly decays into multiple different pathways, such as enhanced electromagnetic fields, an abundance of hot carriers, and dramatically elevated local thermal environments. To better understand the various chemistries that are enabled by plasmonic materials and the associated mechanisms driving these processes, we have employed surface-enhanced Raman spectroscopy to interrogate a plethora of plasmon-molecule coupled systems. Our initial studies investigated the relationship between the plasmonic local fields and a well-established plasmon-driven photochemical reaction. We found that there were no observable correlations between the two in our studies and identified a competing degradation pathway for the studied analytes. In addition to exploring well-studied plasmon-induced chemical photoreactions, we have highlighted two new reactions that were accessed on the gold film-over-nanosphere substrates. First, we were able to induce and subsequently monitor a selective intramolecular methyl migration on N-methylpyridinium using surface-enhanced Raman spectroscopy. This work emphasizes the growing potential of initiating highly-selective chemistries with plasmonic materials for synthetic or redox purposes. The second previously unreported plasmon-driven reaction involves the double cleavage of the C-N bond on a pair of viologen derivatives. While these viologens have traditionally been employed as robust redox species, the unique and highly-powerful plasmonic local fields allowed the viologens to access an entirely new reaction pathway to transform into 4,4’-bipyridine. Lastly, we discuss our experimental approaches towards transiently studying the mechanism behind plasmon-mediated hot electron transfer. Using ultrafast surface-enhanced Raman spectroscopy, we interrogated the transient dynamics that occurred between surface plasmons and a bevy of electron accepting chemical adsorbates. Ultimately, the primary goal of this work is to provide a quantitative description of the transient interactions, which will assist in increasing the reported efficiencies and yields of plasmon-mediated chemical reaction and inspire the rational design of plasmonically-powered devices.
Subjects/Keywords: Plasmonics; SERS; Spectroscopy; Ultrafast
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APA (6th Edition):
Brooks, J. (2019). Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/217170
Chicago Manual of Style (16th Edition):
Brooks, James. “Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry.” 2019. Doctoral Dissertation, University of Minnesota. Accessed March 06, 2021.
http://hdl.handle.net/11299/217170.
MLA Handbook (7th Edition):
Brooks, James. “Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry.” 2019. Web. 06 Mar 2021.
Vancouver:
Brooks J. Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry. [Internet] [Doctoral dissertation]. University of Minnesota; 2019. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11299/217170.
Council of Science Editors:
Brooks J. Surface-Enhanced Raman Spectroscopy as a Probe to Understand Plasmon-Mediated Photochemistry. [Doctoral Dissertation]. University of Minnesota; 2019. Available from: http://hdl.handle.net/11299/217170
Colorado School of Mines
27.
Greco, Michael J.
Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses.
Degree: PhD, Physics, 2016, Colorado School of Mines
URL: http://hdl.handle.net/11124/170115
► Chirped pulse amplication of ultrafast laser pulses has become an essential technology in the elds of micromachining, tissue ablation, and microscopy. With specically tailored pulses…
(more)
▼ Chirped pulse amplication of
ultrafast laser pulses has become an essential technology in the elds of micromachining, tissue ablation, and microscopy. With specically tailored pulses of light we have been able to begin investigation into lab-on-a-chip technology, which has the potential of revolutionizing the medical industry. Advances in microscopy have allowed sub diraction limited resolution to become a reality as well as lensless imaging of single molecules. An intimate knowledge of
ultrafast optical pulses, the ability to manipulate an optical spectrum and generate an optical pulse of a specic temporal shape, allows us to continue pushing these elds forward as well as open new ones. This thesis investigates the spatio-temporal construction of pulses which are simultaneously spatio-temporally focused (SSTF) and about their current and future applications. By laterally chirping a compressed laser pulse we have conned the peak intensity to a shorter distance along the optical axis than can be achieved by conventional methods. This also brings about interesting changes to the structure of the pulse intensity such as pulse front tilt (PFT), an eect where the pulse energy is delayed across the focal spot at the focal plane by longer durations than the pulse itself. Though these pulses have found utility in microscopy and micromachining, in-situ methods for characterizing them spatially and temporally are not yet wide spread. I present here an in-situ characterization technique for both spatial and temporal diagnosis of SSTF pulses. By performing a knife-edge scan and collecting the light in a spectrometer, the relative spectral position as well as beam size can be deduced. Temporal characterization is done by dispersion scan, where a second harmonic crystal through the beam focus. Combining the unknown phase of the pulse with the known phase (a result of angular dispersion) allows the unknown phase to be extracted from the second harmonic spectra.
Advisors/Committee Members: Durfee, Charles G. (advisor), Squier, Jeff A. (committee member), Marr, David W. M. (committee member), Flammer, P. David (committee member), Kohl, Patrick B. (Patrick Brian) (committee member).
Subjects/Keywords: laser beam characterization; pulse compression; ultrafast optics; ultrafast technology
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Greco, M. J. (2016). Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/170115
Chicago Manual of Style (16th Edition):
Greco, Michael J. “Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses.” 2016. Doctoral Dissertation, Colorado School of Mines. Accessed March 06, 2021.
http://hdl.handle.net/11124/170115.
MLA Handbook (7th Edition):
Greco, Michael J. “Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses.” 2016. Web. 06 Mar 2021.
Vancouver:
Greco MJ. Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2016. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/11124/170115.
Council of Science Editors:
Greco MJ. Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses. [Doctoral Dissertation]. Colorado School of Mines; 2016. Available from: http://hdl.handle.net/11124/170115
28.
Berstermann, Thorsten.
Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures.
Degree: 2010, Technische Universität Dortmund
URL: http://hdl.handle.net/2003/27166
► In this work experiments on the interaction of picosecond strain wave packets with semiconductor quantum wells and optical microcavities are presented. The focus is on…
(more)
▼ In this work experiments on the
interaction of picosecond strain wave packets with semiconductor
quantum wells and optical microcavities are presented. The focus is
on the transient change of the semiconductors optical properties
due to the applied dynamical strain. The strain pulses are injected
into the sample structures using laser heating of a thin aluminum
film, which was deposited on the backside of each sample. After
propagating through a GaAs substrate, these strain pulses impact on
the structured semiconductors at the front side of the sample. The
induced changes in the optical properties are monitored by optical
reflectance and photoluminescense spectroscopy. At first optical
reflectance spectra of the cavity mode in a II-VI semiconductor
based planar microcavity are presented. The modulation occurs when
the strain pulse passes interfaces of the layered cavity structure
at which the electric field has an antinode. Maximum modulation is
reached when the pulse enters or leaves the central cavity layer.
The mode energy shifts in the cavity with a finesse of about 2000
are comparable to its mode linewidth, which shows that the proposed
technique is prospective for
ultrafast optical switching. Further
the effect of high amplitude strain waves on a II-VI quantum well
is investigated. Acoustic solitons formed during the propagation of
the picosecond strain wave in the GaAs substrate lead to exciton
resonance energy shifts of up to 10 meV in the quantum well as well
as to
ultrafast frequency modulation, i.e., chirping, of the
exciton transition. Both kind of semiconductor structures have been
combined in a III-V semiconductor quantum well microcavity in the
strong-coupling regime. A domain can be obtained in which large
variations in the optical frequency are induced on time scales
shorter than the polariton decoherence. Under these conditions
characteristic sidebands which are spectral fingerprints of the
terahertz modulation process appear in the reflectance spectra near
the polariton resonance. In extreme cases of the polariton
resonance energy modulation the strong coupling regime effectively
is left. Thereby antiphase oscillations are observed concerning the
intensity of the polariton modes and the photonic cavity mode.
These oscillations occur on a timescale corresponding to the
minimum normal mode splitting of the coupled system. Additionally
ultrafast modulation of the photoluminescence intensity from the
lower polariton branch is observed.
Advisors/Committee Members: Bayer, M..
Subjects/Keywords: Cavity; Modulation;
Nanostructure; Strain; Ultrafast; 530
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APA (6th Edition):
Berstermann, T. (2010). Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures. (Thesis). Technische Universität Dortmund. Retrieved from http://hdl.handle.net/2003/27166
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Berstermann, Thorsten. “Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures.” 2010. Thesis, Technische Universität Dortmund. Accessed March 06, 2021.
http://hdl.handle.net/2003/27166.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Berstermann, Thorsten. “Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures.” 2010. Web. 06 Mar 2021.
Vancouver:
Berstermann T. Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures. [Internet] [Thesis]. Technische Universität Dortmund; 2010. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2003/27166.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Berstermann T. Ultrafast piezospectroscopy of
semiconductor micro- and nanostructures. [Thesis]. Technische Universität Dortmund; 2010. Available from: http://hdl.handle.net/2003/27166
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Michigan
29.
Kiefer, Laura.
Ultrafast Spectral Dynamics of a Rhenium Photocatalyst.
Degree: PhD, Chemistry, 2016, University of Michigan
URL: http://hdl.handle.net/2027.42/135909
► This dissertation investigates the photo-initiated CO2 reduction catalyst, Re(bpy)(CO)3Cl, in multiple states along the photocatalytic cycle with the goal of understanding the influence of electrostatics…
(more)
▼ This dissertation investigates the photo-initiated CO2 reduction catalyst, Re(bpy)(CO)3Cl, in multiple states along the photocatalytic cycle with the goal of understanding the influence of electrostatics and solvent on each step. Two-dimensional infrared (2DIR) spectroscopy was used to characterize the electronic ground state dynamics of the Re photocatalyst, including several derivatives, in multiple solvents. Though insensitive to the substituents, spectral dynamics do correlate with the solvent's nucleophilicity. Transient-2DIR experiments enabled the first ever characterization of a quasi-equilibrated electronic excited state. Electronic excitation at 400 nm followed by equilibration in the triplet metal-to-ligand charge transfer state, provided direct access to dynamics using a time-delayed 2DIR pulse sequence. Relative to the ground state, we observe a two-fold slowdown in spectral dynamics as sensed by the in-phase symmetric vibrational mode and a decrease in the vibrational lifetime by a factor of five. Transient 2DIR characterizes catalytically relevant, long-lived electronic excited states independent of any ground state dynamics.
Introducing the sacrificial electron donor triethanolamine (TEOA) revealed a concentration dependent slowdown of the Re spectral dynamics, indicating both preferential solvation and solvent exchange. Preferential solvation was confirmed after UV-Vis pump/IR probe experiments showed the appearance of the singly reduced, intermolecular electron transfer product on a timescale faster than diffusion (<70 ps). This result highlights a previously ignored mechanistic aspect of this essential electron transfer reaction.
Re photocatalysis experiments were supplemented by additional investigations into solvation and molecular flexibility. In a solution of the Re complex and Na+SCN- in THF, 2DIR experiments revealed an intermolecular vibrational energy transfer between the Re complex and Na+SCN- on a timescale distinct from the equilibrium fluctuations of the two individual donor and acceptor bands involved, indicating non-Gaussian dynamics. The next work isolated polymer flexibility chosen specifically because of its site-specific vibrational probes. The chain ends spectrally diffuse slower than do the inner chain sites and going from dilute solution to a solvent-free film, the heterogeneity in site dynamics become reduced due to the crowding influence of neighboring molecules. This experiment was supported with a coarse grained model of the polymer which showed essentially quantitative agreement with measured relative dynamics.
Advisors/Committee Members: Kubarych, Kevin Joel (committee member), Sih, Vanessa (committee member), Geva, Eitan (committee member), Sension, Roseanne J (committee member).
Subjects/Keywords: ultrafast dynamics; photocatalyst; infrared spectroscopy; Chemistry; Science
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APA ·
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APA (6th Edition):
Kiefer, L. (2016). Ultrafast Spectral Dynamics of a Rhenium Photocatalyst. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/135909
Chicago Manual of Style (16th Edition):
Kiefer, Laura. “Ultrafast Spectral Dynamics of a Rhenium Photocatalyst.” 2016. Doctoral Dissertation, University of Michigan. Accessed March 06, 2021.
http://hdl.handle.net/2027.42/135909.
MLA Handbook (7th Edition):
Kiefer, Laura. “Ultrafast Spectral Dynamics of a Rhenium Photocatalyst.” 2016. Web. 06 Mar 2021.
Vancouver:
Kiefer L. Ultrafast Spectral Dynamics of a Rhenium Photocatalyst. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2027.42/135909.
Council of Science Editors:
Kiefer L. Ultrafast Spectral Dynamics of a Rhenium Photocatalyst. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/135909
University of Michigan
30.
Daley, Kimberly.
Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study.
Degree: PhD, Chemistry, 2018, University of Michigan
URL: http://hdl.handle.net/2027.42/147552
► Water-solute interactions still remain a challenge to study experimentally, though they are critical to protein and biomacromolecule stability, structure, and function. Hydration dynamics at interfaces…
(more)
▼ Water-solute interactions still remain a challenge to study experimentally, though they are critical to protein and biomacromolecule stability, structure, and function. Hydration dynamics at interfaces are generally slower than bulk water. While many investigations into the dynamics of water using advanced spectroscopy methods have occurred, considerably less specific attention has been paid to biologically relevant highly crowded solutions. Macromolecular crowding is the result of both steric and chemical interactions of the crowding agent with the targeted molecule of study. Considering steric effects of crowding agents is not enough, and studies of chemical interactions are increasingly being done. Crowding agents typically are polymers, proteins, reverse micelles, or hydrogels, and in this study, we focus on polymers. We seek to understand how polymer crowders affect hydration dynamics. Using
ultrafast two-dimensional infrared (2D-IR) spectroscopy of a new water-soluble transition metal complex acting as a vibrational probe, we look at a range of polymers at various lengths, concentrations, and temperatures. We find that PEG, which exhibits unusual structural and thermodynamic trends, has a very stable hydration shell at room temperature. The stable hydration shell promotes bulk like hydration dynamics even at high concentrations and viscosities. From temperature variance experiments, we calculate activation energies and find that the results are similar to activation energies of water. Our studies provide fundamental information about the hydration dynamics of concentrated polymer solutions and we find evidence for distinct dynamics sensed by the probe depending on the crowding agent.
Advisors/Committee Members: Kubarych, Kevin Joel (committee member), Sih, Vanessa (committee member), Biteen, Julie Suzanne (committee member), Zgid, Dominika Kamila (committee member).
Subjects/Keywords: ultrafast spectroscopy; macromolecular crowding; Chemistry; Science
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APA ·
Chicago ·
MLA ·
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APA (6th Edition):
Daley, K. (2018). Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/147552
Chicago Manual of Style (16th Edition):
Daley, Kimberly. “Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study.” 2018. Doctoral Dissertation, University of Michigan. Accessed March 06, 2021.
http://hdl.handle.net/2027.42/147552.
MLA Handbook (7th Edition):
Daley, Kimberly. “Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study.” 2018. Web. 06 Mar 2021.
Vancouver:
Daley K. Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Mar 06].
Available from: http://hdl.handle.net/2027.42/147552.
Council of Science Editors:
Daley K. Solvation Dynamics of Concentrated Aqueous Polymer Mixtures: A Two Dimensional Infrared Spectroscopy Study. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/147552
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Open Access Theses and Dissertations
