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You searched for subject:(microrings). Showing records 1 – 2 of 2 total matches.

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University of Southern California

1. Gupta, Greeshma. Microring resonator based filters and modulators: optical coupling control and applications to digital communications.

Degree: PhD, Electrical Engineering, 2008, University of Southern California

Optical microring resonator based filters and modulators are the potential building blocks of Photonic VLSI circuits. The ratio of optical power coupled between ring and bus waveguides in microring based devices is crucial to the desired device characteristics, and is the subject of study in the first part of this thesis. High-intensity laser photobleaching is used to demonstrate precise and fast post-fabrication trimming of coupling in 1) high-Q passive polymer microrings vertically coupled to chromophore-doped waveguides, and in 2) laterally coupled electro-optic ring modulators. In the first case, a decrease in coupling causes a 33% decrease in bandwidth, and in the second case an increase in coupling causes a 6-dB increase in extinction ratio. The latter ring is brought closer to critical coupling, as confirmed by phase characterization results, which indicate a significant increase in peak negative group-delay of the undercoupled ring. Photobleaching is an all-optical method of coupling control, via change of the refractive index of chromophore-doped polymer material, in the coupling region. A simple directional-coupler based mathematical model is developed for both cases, which analytically estimates the experimental change in coupling with index decrease.; We also develop a model for predicting the temporal evolution of refractive index change, averaged over the bleached thin-film depth. The concept of saturated absorption is applied to model the effect that high-intensity of light has on photobleaching-induced index change. The values of the photostability figure-of-merit and/or saturation-intensity for modern n-conjugated non-linear-optical chromophores, such as CLD-1 and AJL8, are obtained here by fitting experimental data.; The second part of this thesis explores applications of microring based devices to digital optical communications  – both quantum and classical. A novel device is proposed, which comprises of Cascaded Over- and Under-coupled Resonators (COUR). COUR can be used as a notch filter and phase modulator that overcomes the trade-offs of extinction-ratio-group-delay and sensitivity-bandwidth. Applications in Quantum-Key-Distribution are proposed. Finally, designs of polymer microring based Differential-Phase-Shift-Keyed modulator and demodulator are proposed. The above proposed modulators are based either on novel chromophore-polymer material, corona poled to obtain high electro-optic coefficient, or on thin-film lithium niobatetechnology, also explored here. Advisors/Committee Members: Steier, William H. (Committee Chair), Dapkus, P. Daniel (Committee Member), Goo, Edward K. (Committee Member).

Subjects/Keywords: microrings; coupling; communications; polymer; photobleaching

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

APA (6th Edition):

Gupta, G. (2008). Microring resonator based filters and modulators: optical coupling control and applications to digital communications. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/74043/rec/4068

Chicago Manual of Style (16th Edition):

Gupta, Greeshma. “Microring resonator based filters and modulators: optical coupling control and applications to digital communications.” 2008. Doctoral Dissertation, University of Southern California. Accessed December 06, 2019. http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/74043/rec/4068.

MLA Handbook (7th Edition):

Gupta, Greeshma. “Microring resonator based filters and modulators: optical coupling control and applications to digital communications.” 2008. Web. 06 Dec 2019.

Vancouver:

Gupta G. Microring resonator based filters and modulators: optical coupling control and applications to digital communications. [Internet] [Doctoral dissertation]. University of Southern California; 2008. [cited 2019 Dec 06]. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/74043/rec/4068.

Council of Science Editors:

Gupta G. Microring resonator based filters and modulators: optical coupling control and applications to digital communications. [Doctoral Dissertation]. University of Southern California; 2008. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/74043/rec/4068


University of Colorado

2. Wade, Mark T. Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor.

Degree: PhD, 2015, University of Colorado

For the first time, high-performance photonic devices and electronic-photonic systems-on-chip are monolithically integrated in an advanced CMOS microelectronics fabrication process. This includes a silicon optical resonator termed the "spoked-ring" cavity that meets the constraints of thin-SOI microelectronics CMOS processes and enables energy efficient modulators and thermally tunable filters. For low-loss fiber-to-chip optical coupling, a phased-array antenna concept is demonstrated, and the 45 nm CMOS microelectronics process is shown to support a near ideal implementation of the device using the crystalline silicon and polysilicon material layers that comprise the active region and gate, respectively, of the native MOSFET transistors. The active devices and vertical grating couplers are implemented in large-scale electronic-photonic systems-on-chip to demonstrate a wavelength stabilized, microring-based chip-to-chip communications link and an 11-channel wavelength division multiplexed (WDM) transmitter. The link is shown to be robust against thermal environmental variations which is critical for operation in realistic systems. The chip-to-chip link is then used to demonstrate a CPU-to-memory communication link, the first demonstration of its kind. The first microprocessor with photonic I/O is demonstrated as part of this work, with substantial implications for computer architecture. Advanced photonic device technology demonstrations, including photonic crystals, a quantum-correlated photon-pair source, an active photonic device platform in a 32 nm SOI node, and a 180 nm bulk silicon process, are presented to show the wide range of applications that monolithic integration could support in the future of photonics. These results taken together show that monolithic integration directly into CMOS microelectronics processes does allow high performance photonics, and is a viable approach to build large-scale electronic-photonic systems with a realistic path to commercial technologies. Advisors/Committee Members: Miloš Popović, Vladimir Stojanović, Anatol Khilo, Kelvin Wagner, Robert McLeod.

Subjects/Keywords: microrings; monolithic integration; optical communication; photonic systems-on-chip; silicon photonics; vertical grating couplers; Semiconductor and Optical Materials

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

APA (6th Edition):

Wade, M. T. (2015). Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/ecen_gradetds/139

Chicago Manual of Style (16th Edition):

Wade, Mark T. “Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor.” 2015. Doctoral Dissertation, University of Colorado. Accessed December 06, 2019. https://scholar.colorado.edu/ecen_gradetds/139.

MLA Handbook (7th Edition):

Wade, Mark T. “Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor.” 2015. Web. 06 Dec 2019.

Vancouver:

Wade MT. Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor. [Internet] [Doctoral dissertation]. University of Colorado; 2015. [cited 2019 Dec 06]. Available from: https://scholar.colorado.edu/ecen_gradetds/139.

Council of Science Editors:

Wade MT. Devices and Systems-on-Chip for Photonic Communication Links in a Microprocessor. [Doctoral Dissertation]. University of Colorado; 2015. Available from: https://scholar.colorado.edu/ecen_gradetds/139

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