subject:(THz Femtosecond)

1. Liu, Xuan. Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques.

Degree: Docteur es, Physique, 2018, Sorbonne université

URL: http://www.theses.fr/2018SORUS146

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Le but de mes recherches est d'étudier les premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques (Co, Ni et Fe ...) en utilisant… (more)

Subjects/Keywords: Désaimantation ultrarapide; Materiaux ferromagnetique; Laser femtoseconde; Split et délai; THz femtosecond; Transport superdiffusif; Ultrafast Demagnetization; Ferromagnetic materials; Femtosecond laser; Split and delay; THz Femtosecond; Super-diffusive spin-transport; 538.4

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Liu, X. (2018). Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques. (Doctoral Dissertation). Sorbonne université. Retrieved from http://www.theses.fr/2018SORUS146

Chicago Manual of Style (16^th Edition):

Liu, Xuan. “Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques.” 2018. Doctoral Dissertation, Sorbonne université. Accessed April 21, 2021. http://www.theses.fr/2018SORUS146.

MLA Handbook (7^th Edition):

Liu, Xuan. “Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques.” 2018. Web. 21 Apr 2021.

Vancouver:

Liu X. Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques. [Internet] [Doctoral dissertation]. Sorbonne université; 2018. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2018SORUS146.

Council of Science Editors:

Liu X. Investigation of the early time period of ultrafast magnetization dynamics : Étude des premiers instants de la désaimantation ultrarapide dans divers matériaux ferromagnétiques. [Doctoral Dissertation]. Sorbonne université; 2018. Available from: http://www.theses.fr/2018SORUS146

Rice University

2. Chen, Peiyu. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.

Degree: PhD, Electrical & Computer Eng., 2018, Rice University

URL: http://hdl.handle.net/1911/102474

► Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications,… (more)

▼ Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications, for example, high-resolution 3D imaging, high-speed wireless communication, broadband spectroscopy, etc. Existing methods for impulse generation have the following drawbacks: First, photonics solutions are usually not compatible with silicon technologies, i.e. CMOS and BiCMOS, impeding higher level SOC designs; Second, electronic oscillator-based solutions usually require phase-locked loop (PLL) and delay-locked loop (DLL) to ensure coherency of generated impulses, which increases system complexity, power consumption, and die area; Third, electronics digital-to-impulse solutions can be further improved by generating shorter impulses, reducing late-time ringing, and achieving amplitude modulation. In addition, high demands on using silicon technology to generate picosecond or sub-picosecond impulses impose challenges on standard chip characterization methods in both time domain and frequency domain. This dissertation demonstrates three chip designs and one chip characterization method to resolve the aforementioned drawbacks and challenges. The first chip design is to use a CMOS-compatible silicon photonics process technology to design a THz PCA chip, which can radiate 1.14 ps impulses. The prototype silicon photonics chip enables easier integrations with other photonics and electronics devices on a single chip. The second chip design is to implement an asymmetric-VCO-based impulse radiator without requiring any PLL or DLL in a 130 nm SiGe BiCMOS. With on-chip antennas, it radiates 60 ps impulses with less power consumption, system complexity, and die area than conventional oscillator-based solutions. The designed impulse radiator has also been applied for 3D imaging. The last chip design is to apply a new circuit technique, nonlinear Q-switching impedance, to implement a 4 ps impulse radiator with pulse amplitude modulation in a 130 nm SiGe BiCMOS. An optoelectronics-based time-domain characterization method was invented to test the 4 ps impulse radiator, and this new measurement technique shows a significant accuracy improvement compared with standard time-domain methods. The demonstrated techniques in this dissertation show that silicon technology is a promising solution to generating picosecond and even sub-picosecond impulses and it is approaching to the performance of photonics devices. Ultra-broadband silicon-based impulse radiators can be characterized using optoelectronics technology to achieve better measurement accuracy. Advisors/Committee Members: Babakhani, Aydin (advisor).

Subjects/Keywords: integrated circuits; RF; mm-wave; THz; broadband system; picosecond; impulse; on-chip antennas; femtosecond laser

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, P. (2018). Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/102474

Chicago Manual of Style (16^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Doctoral Dissertation, Rice University. Accessed April 21, 2021. http://hdl.handle.net/1911/102474.

MLA Handbook (7^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Web. 21 Apr 2021.

Vancouver:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Internet] [Doctoral dissertation]. Rice University; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1911/102474.

Council of Science Editors:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Doctoral Dissertation]. Rice University; 2018. Available from: http://hdl.handle.net/1911/102474

Rice University

3. Chen, Peiyu. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.

Degree: PhD, Electrical & Computer Eng., 2018, Rice University

URL: http://hdl.handle.net/1911/102475

► Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications,… (more)

▼ Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications, for example, high-resolution 3D imaging, high-speed wireless communication, broadband spectroscopy, etc. Existing methods for impulse generation have the following drawbacks: First, photonics solutions are usually not compatible with silicon technologies, i.e. CMOS and BiCMOS, impeding higher level SOC designs; Second, electronic oscillator-based solutions usually require phase-locked loop (PLL) and delay-locked loop (DLL) to ensure coherency of generated impulses, which increases system complexity, power consumption, and die area; Third, electronics digital-to-impulse solutions can be further improved by generating shorter impulses, reducing late-time ringing, and achieving amplitude modulation. In addition, high demands on using silicon technology to generate picosecond or sub-picosecond impulses impose challenges on standard chip characterization methods in both time domain and frequency domain. This dissertation demonstrates three chip designs and one chip characterization method to resolve the aforementioned drawbacks and challenges. The first chip design is to use a CMOS-compatible silicon photonics process technology to design a THz PCA chip, which can radiate 1.14 ps impulses. The prototype silicon photonics chip enables easier integrations with other photonics and electronics devices on a single chip. The second chip design is to implement an asymmetric-VCO-based impulse radiator without requiring any PLL or DLL in a 130 nm SiGe BiCMOS. With on-chip antennas, it radiates 60 ps impulses with less power consumption, system complexity, and die area than conventional oscillator-based solutions. The designed impulse radiator has also been applied for 3D imaging. The last chip design is to apply a new circuit technique, nonlinear Q-switching impedance, to implement a 4 ps impulse radiator with pulse amplitude modulation in a 130 nm SiGe BiCMOS. An optoelectronics-based time-domain characterization method was invented to test the 4 ps impulse radiator, and this new measurement technique shows a significant accuracy improvement compared with standard time-domain methods. The demonstrated techniques in this dissertation show that silicon technology is a promising solution to generating picosecond and even sub-picosecond impulses and it is approaching to the performance of photonics devices. Ultra-broadband silicon-based impulse radiators can be characterized using optoelectronics technology to achieve better measurement accuracy. Advisors/Committee Members: Babakhani, Aydin (advisor).

Subjects/Keywords: integrated circuits; RF; mm-wave; THz; broadband system; picosecond; impulse; on-chip antennas; femtosecond laser

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, P. (2018). Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/102475

Chicago Manual of Style (16^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Doctoral Dissertation, Rice University. Accessed April 21, 2021. http://hdl.handle.net/1911/102475.

MLA Handbook (7^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Web. 21 Apr 2021.

Vancouver:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Internet] [Doctoral dissertation]. Rice University; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1911/102475.

Council of Science Editors:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Doctoral Dissertation]. Rice University; 2018. Available from: http://hdl.handle.net/1911/102475

Rice University

4. Chen, Peiyu. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.

Degree: PhD, Electrical & Computer Eng., 2018, Rice University

URL: http://hdl.handle.net/1911/102473

► Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications,… (more)

▼ Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications, for example, high-resolution 3D imaging, high-speed wireless communication, broadband spectroscopy, etc. Existing methods for impulse generation have the following drawbacks: First, photonics solutions are usually not compatible with silicon technologies, i.e. CMOS and BiCMOS, impeding higher level SOC designs; Second, electronic oscillator-based solutions usually require phase-locked loop (PLL) and delay-locked loop (DLL) to ensure coherency of generated impulses, which increases system complexity, power consumption, and die area; Third, electronics digital-to-impulse solutions can be further improved by generating shorter impulses, reducing late-time ringing, and achieving amplitude modulation. In addition, high demands on using silicon technology to generate picosecond or sub-picosecond impulses impose challenges on standard chip characterization methods in both time domain and frequency domain. This dissertation demonstrates three chip designs and one chip characterization method to resolve the aforementioned drawbacks and challenges. The first chip design is to use a CMOS-compatible silicon photonics process technology to design a THz PCA chip, which can radiate 1.14 ps impulses. The prototype silicon photonics chip enables easier integrations with other photonics and electronics devices on a single chip. The second chip design is to implement an asymmetric-VCO-based impulse radiator without requiring any PLL or DLL in a 130 nm SiGe BiCMOS. With on-chip antennas, it radiates 60 ps impulses with less power consumption, system complexity, and die area than conventional oscillator-based solutions. The designed impulse radiator has also been applied for 3D imaging. The last chip design is to apply a new circuit technique, nonlinear Q-switching impedance, to implement a 4 ps impulse radiator with pulse amplitude modulation in a 130 nm SiGe BiCMOS. An optoelectronics-based time-domain characterization method was invented to test the 4 ps impulse radiator, and this new measurement technique shows a significant accuracy improvement compared with standard time-domain methods. The demonstrated techniques in this dissertation show that silicon technology is a promising solution to generating picosecond and even sub-picosecond impulses and it is approaching to the performance of photonics devices. Ultra-broadband silicon-based impulse radiators can be characterized using optoelectronics technology to achieve better measurement accuracy. Advisors/Committee Members: Babakhani, Aydin (advisor).

Subjects/Keywords: integrated circuits; RF; mm-wave; THz; broadband system; picosecond; impulse; on-chip antennas; femtosecond laser

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, P. (2018). Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/102473

Chicago Manual of Style (16^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Doctoral Dissertation, Rice University. Accessed April 21, 2021. http://hdl.handle.net/1911/102473.

MLA Handbook (7^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Web. 21 Apr 2021.

Vancouver:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Internet] [Doctoral dissertation]. Rice University; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1911/102473.

Council of Science Editors:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Doctoral Dissertation]. Rice University; 2018. Available from: http://hdl.handle.net/1911/102473

Rice University

5. Chen, Peiyu. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.

Degree: PhD, Engineering, 2018, Rice University

URL: http://hdl.handle.net/1911/102472

► Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications,… (more)

▼ Short impulses in millimeter-wave (mm-wave) and THz regimes (30 GHz - 30 THz) have a potentially large bandwidth that can be exploited for various applications, for example, high-resolution 3D imaging, high-speed wireless communication, broadband spectroscopy, etc. Existing methods for impulse generation have the following drawbacks: First, photonics solutions are usually not compatible with silicon technologies, i.e. CMOS and BiCMOS, impeding higher level SOC designs; Second, electronic oscillator-based solutions usually require phase-locked loop (PLL) and delay-locked loop (DLL) to ensure coherency of generated impulses, which increases system complexity, power consumption, and die area; Third, electronics digital-to-impulse solutions can be further improved by generating shorter impulses, reducing late-time ringing, and achieving amplitude modulation. In addition, high demands on using silicon technology to generate picosecond or sub-picosecond impulses impose challenges on standard chip characterization methods in both time domain and frequency domain. This dissertation demonstrates three chip designs and one chip characterization method to resolve the aforementioned drawbacks and challenges. The first chip design is to use a CMOS-compatible silicon photonics process technology to design a THz PCA chip, which can radiate 1.14 ps impulses. The prototype silicon photonics chip enables easier integrations with other photonics and electronics devices on a single chip. The second chip design is to implement an asymmetric-VCO-based impulse radiator without requiring any PLL or DLL in a 130 nm SiGe BiCMOS. With on-chip antennas, it radiates 60 ps impulses with less power consumption, system complexity, and die area than conventional oscillator-based solutions. The designed impulse radiator has also been applied for 3D imaging. The last chip design is to apply a new circuit technique, nonlinear Q-switching impedance, to implement a 4 ps impulse radiator with pulse amplitude modulation in a 130 nm SiGe BiCMOS. An optoelectronics-based time-domain characterization method was invented to test the 4 ps impulse radiator, and this new measurement technique shows a significant accuracy improvement compared with standard time-domain methods. The demonstrated techniques in this dissertation show that silicon technology is a promising solution to generating picosecond and even sub-picosecond impulses and it is approaching to the performance of photonics devices. Ultra-broadband silicon-based impulse radiators can be characterized using optoelectronics technology to achieve better measurement accuracy. Advisors/Committee Members: Babakhani, Aydin (advisor).

Subjects/Keywords: integrated circuits; RF; mm-wave; THz; broadband system; picosecond; impulse; on-chip antennas; femtosecond laser

Record Details Similar Records Cite « Share

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, P. (2018). Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/102472

Chicago Manual of Style (16^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Doctoral Dissertation, Rice University. Accessed April 21, 2021. http://hdl.handle.net/1911/102472.

MLA Handbook (7^th Edition):

Chen, Peiyu. “Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon.” 2018. Web. 21 Apr 2021.

Vancouver:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Internet] [Doctoral dissertation]. Rice University; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1911/102472.

Council of Science Editors:

Chen P. Design Techniques and Measurement Methods for Broadband Millimeter-Wave and THz Systems in Silicon. [Doctoral Dissertation]. Rice University; 2018. Available from: http://hdl.handle.net/1911/102472

Université de Grenoble

6. Patin, Benjamin. Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch.

Degree: Docteur es, Sciences et technologie industrielles, 2013, Université de Grenoble

URL: http://www.theses.fr/2013GRENT076

► Le sujet de la thèse a porté sur la mise au point, la caractérisation et l'utilisation de matériaux semi-conducteurs, au sein desquels les porteurs libres… (more)

▼ Le sujet de la thèse a porté sur la mise au point, la caractérisation et l'utilisation de matériaux semi-conducteurs, au sein desquels les porteurs libres ont un temps de vie extrêmement brefs (picoseconde ou sub-picoseconde), pour réaliser des antennes photoconductrices émettrices ou détectrices de rayonnement électromagnétique térahertz (THz). Contrairement au semi-conducteur LTG-GaAs (low temperature grown GaAs) à la technologie bien dominée et aux performances exceptionnelles lorsque photo-excité par des impulsions lasers de longueurs d'onde typiquement inférieures à 0,8 µm, le travail portait ici sur des matériaux permettant l'emploi de lasers dont les longueurs d'onde sont celles des télécommunications optiques, à savoir aux alentours de 1,5 µm. L'intérêt est de bénéficier de la technologie mature de ces lasers, et du coût relativement modique des composants pour les télécommunications optiques. Pour réaliser des antennes THz performantes et efficaces, le matériau semi-conducteur doit présenter plusieurs qualités : vie des porteurs libres très courte, grande mobilité des porteurs, haute résistivité hors éclairement, et bonne structure cristallographique pour éviter les claquages électriques. Pour obtenir une courte durée de vie, on introduit un grand nombre de pièges dans le semi-conducteur, qui capturent efficacement les électrons libres. Pour les matériaux de type InGaAs employés à 1,5 µm, le problème est que le niveau en énergie de ces pièges, par exemple pour les matériaux épitaxiés à basse température, est très proche de la bande de conduction du semi-conducteur. Cela est équivalent à un dopage n du matériau, ce qui en diminue fortement sa résistivité hors éclairement. Plusieurs solutions ont été apportées par différents laboratoires : compensation par dopage p pour les matériaux épitaxiés à basse température, bombardement ionique, implantation ionique, ou même structures à couches alternées où la photo-génération et la recombinaison des porteurs libres se produisent à des endroits différents. Le but du travail de thèse était de fabriquer des matériaux préparés suivant ces différentes techniques, de les caractériser et de comparer leurs performances pour l'optoélectronique THz. Les semi-conducteurs à étudier étaient de type InGaAs comme déjà publiés par la concurrence, l'originalité de thèse portant sur la comparaison de ces différents matériaux et si possible leur optimisation,. Au cours de ce travail de thèse, de nombreuses couches d'InGaAs ont été épitaxiées, en faisant varier les paramètres de dépôt, et des antennes THz ont été fabriquées. Les couches ont été caractérisées du point de vue cristallographique, ainsi que pour la conductivité électrique DC (mesures 4 pointes, mobilité Hall…), les propriétés d'absorption optique (spectroscopie visible et IR), la durée de vie des porteurs par mesure optique pompe-sonde. Pour les couches épitaxiées à basse température, l'influence d'un recuit thermique ainsi que du dopage en béryllium ont été étudiés. Dans le cas de couches bombardées ou implantées, plusieurs… Advisors/Committee Members: Coutaz, Jean-Louis (thesis director), Salem, Bassem (thesis director).

Subjects/Keywords: Térahertz (THz); Semi-conducteur InGaAs; Antenne photoconductrice; Laser femtoseconde; Optoélectronique; Infrarouge lointain; Terahertz (THz; InGaAs semi-conductor; Photoconductive antenna; Femtosecond laser; Optoelectronics; Far infrared

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Patin, B. (2013). Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch. (Doctoral Dissertation). Université de Grenoble. Retrieved from http://www.theses.fr/2013GRENT076

Chicago Manual of Style (16^th Edition):

Patin, Benjamin. “Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch.” 2013. Doctoral Dissertation, Université de Grenoble. Accessed April 21, 2021. http://www.theses.fr/2013GRENT076.

MLA Handbook (7^th Edition):

Patin, Benjamin. “Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch.” 2013. Web. 21 Apr 2021.

Vancouver:

Patin B. Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch. [Internet] [Doctoral dissertation]. Université de Grenoble; 2013. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2013GRENT076.

Council of Science Editors:

Patin B. Matériaux et Dispositifs optoélectroniques pour la génération et la détection de signaux THz impulsionnels par photocommutation à 1,55µm : Optoelectronic devices for THz emission and detection by 1,55µm femtosecond laser photoswitch. [Doctoral Dissertation]. Université de Grenoble; 2013. Available from: http://www.theses.fr/2013GRENT076

7. Athanasios, Margiolakis. Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς.

Degree: 2019, University of Crete (UOC); Πανεπιστήμιο Κρήτης

URL: http://hdl.handle.net/10442/hedi/45355

►

In this thesis research, is presented the study and development of the first photoconductive antenna for generating Terahertz (THz), made of a Gallium Arsenide (GaAs)… (more)

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In this thesis research, is presented the study and development of the first photoconductive antenna for generating Terahertz (THz), made of a Gallium Arsenide (GaAs) substrate, treated with femtosecond laser pulses, demonstrating increased performance compared to non-ablated antennas. Ripples are observed on the surface of the device after the laser ablation and we assume they are responsible for the increased performance. They are studied theoretically and experimentally, in order to explain this behavior. For the first time, a theoretical model is made to study GaAs ultrafast dynamics under irradiation of femtosecond laser pulses. In this model, energy balance equations are used to explain the ultrashort time-scales and evolution of dynamics. They are resolved numerically due to their coupled non-linear complexity, while the stability of the solution is ensured. Evolution of carrier density, electron and lattice temperature are the measured variables in order to obtain the thermal response of GaAs. The optical properties with dependence to fluence and pulse duration of the laser are studied, namely reflectivity and dielectric constant. The ripple wavelength is numerically calculated from our model and compared to our experimental data. The material’s damage threshold dependence on laser pulse duration was also calculated.A parametric analysis based on the properties of the ablation laser pulse and how it affects the ripples was performed and the measured properties are the applied power intensity, the overlapping area on each spot, polarization angle and number of pulses per spot. In the last chapter, using THz-TDS setup, the laser ablated GaAs antenna is measured for its THz generation performance and compared to a non-ablated antenna. Despite higher THz efficiency the following I-V measurements of the photocurrent, return lower values. To explain this discrepancy, an Optical Pump THz Probe (OPTP) setup is used to measure the excited carrier lifetime and photoconductivity. Complementary, Fourier Transform Infrared (FTIR) measurements are performed, to confirm higher photo-absorption and Hall Effect measurements are made for measuring the level of doping, sheet concentration and carrier mobility.

Στην παρούσα εργασία παρουσιάζεται η μελέτη και η ανάπτυξη της πρώτης φωτοαγώγιμης κεραίας για παραγωγή Terahertz (THz), κατασκευασμένη από υπόστρωμα Αρσενίδιου του Γαλλίου (GaAs), επεξεργασμένη με παλμούς λέιζερ φεμτοδευτερολέπτων, επιδεικνύοντας αυξημένη απόδοση σε σύγκριση με μη επεξεργασμένες κεραίες. Παρατηρούνται κυματισμοί στην επιφάνεια της διάταξης, μετά την φωτοαποδόμηση με λέιζερ και υποθέτουμε ότι είναι υπεύθυνοι για την αυξημένη απόδοση. Οι κυματισμοί μελετώνται θεωρητικά και πειραματικά, για να εξηγηθεί αυτή τη συμπεριφορά. Για πρώτη φορά, δημιουργείται θεωρητικό μοντέλο για να μελετηθούν οι υπερταχείς δυναμικές του GaAs υπό την επίδραση ακτινοβολίας λέιζερ παλμών φεμτοδευτερολέπτων. Σε αυτό το μοντέλο, χρησιμοποιούνται εξισώσεις ενεργειακής ισορροπίας για να εξηγήσουν τις υπερβραχείς χρονο-κλίμακες και…

Subjects/Keywords: Ακτινοβολία τεραχερτζ; Φωτοαποδόμηση με παλμικό Laser; Φωτοαγωγιμότητα; Θεωρητικό μοντέλο; Υπέρυθρη φασματοσκοπία μέσω μετασχηματισμού Fourier; Παραμετρική ανάλυση; Terahertz radiation; Laser ablation; Femtosecond laser; Photoconductive antenna; Theoretical modeling; THz-Time domain spectroscopy; Parametric analysis; Fast FOURIER transform infrared spectroscopy

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Athanasios, M. (2019). Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς. (Thesis). University of Crete (UOC); Πανεπιστήμιο Κρήτης. Retrieved from http://hdl.handle.net/10442/hedi/45355

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Athanasios, Margiolakis. “Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς.” 2019. Thesis, University of Crete (UOC); Πανεπιστήμιο Κρήτης. Accessed April 21, 2021. http://hdl.handle.net/10442/hedi/45355.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Athanasios, Margiolakis. “Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς.” 2019. Web. 21 Apr 2021.

Vancouver:

Athanasios M. Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς. [Internet] [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2019. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/10442/hedi/45355.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Athanasios M. Ενισχυμένη εκπομπή THz από GaAs με φωτοαποδόμηση από υπερβραχείς παλμούς. [Thesis]. University of Crete (UOC); Πανεπιστήμιο Κρήτης; 2019. Available from: http://hdl.handle.net/10442/hedi/45355

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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Open Access Theses and Dissertations