Frequency Noise Control of Heterogeneous Si/III-V Lasers

<p>Narrow-linewidth lasers have many applications including optical telecommunication, laser spectroscopy, atomic clocks, and light detection and ranging. Conventionally, narrow linewidth lasers have been realized in the form of fiber-based or solid-state lasers. These lasers are bulky and rel...

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Main Author: Kim, Dongwan
Format: Others
Published: 2018
Online Access:https://thesis.library.caltech.edu/10540/13/Dongwan_thesis_2017_final_print.pdf
Kim, Dongwan (2018) Frequency Noise Control of Heterogeneous Si/III-V Lasers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z90Z71G6. https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721 <https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721>
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spelling ndltd-CALTECH-oai-thesis.library.caltech.edu-105402019-10-05T03:04:52Z Frequency Noise Control of Heterogeneous Si/III-V Lasers Kim, Dongwan <p>Narrow-linewidth lasers have many applications including optical telecommunication, laser spectroscopy, atomic clocks, and light detection and ranging. Conventionally, narrow linewidth lasers have been realized in the form of fiber-based or solid-state lasers. These lasers are bulky and relatively expensive, limiting their usage as bench-top systems in laboratory environments. Historically, semiconductor lasers, also known as laser diodes, have served applications where size and cost are important factors, including fiber optic communications. The linewidth of the semiconductor lasers, however, has been limited to the MHz-level, due to high loss in laser cavities and small size.</p> <p>Recently, reduction of the frequency fluctuations in the semiconductor lasers has been achieved, obtaining tens of kHz linewidth, using the heterogeneous Silicon/III-V platform with a new design strategy. In this design, the majority of the optical energy is stored in the low-loss high-Q silicon resonator away from the high-loss III-V active region, requiring the minimal gain from the active region to overcome the reduced modal loss.</p> <p>This work explores the new design strategy further, and demonstrates theoretically and experimentally that the strategy eliminates the frequency fluctuations arising from the amplitude-phase coupling by placing a relaxation resonance frequency at frequencies of a few hundred MHz. Consequently, it becomes possible to obtain a semiconductor laser device possessing sub-kHz quantum-limited linewidths at frequencies of a few GHz (the frequencies of interest in optical telecommunication).</p> <p>In addition to the frequency noise reduction, the strategy turns out to have the additional benefit of accomplishing a coherent and stable lasing operation, even under external reflections. Thus, the new design strategy has the potential to replace the costly, but currently indispensable external optical isolators, which have been traditionally used to maintain the consistent performance of semiconductor lasers in the presence of external reflection.</p> <p>This work paves the way for the design of narrow-linewidth and stable semiconductor lasers that can function without the use of the bulky and costly external components, such as external cavities or optical isolators.</p> 2018 Thesis NonPeerReviewed application/pdf https://thesis.library.caltech.edu/10540/13/Dongwan_thesis_2017_final_print.pdf https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721 Kim, Dongwan (2018) Frequency Noise Control of Heterogeneous Si/III-V Lasers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z90Z71G6. https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721 <https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721> https://thesis.library.caltech.edu/10540/
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description <p>Narrow-linewidth lasers have many applications including optical telecommunication, laser spectroscopy, atomic clocks, and light detection and ranging. Conventionally, narrow linewidth lasers have been realized in the form of fiber-based or solid-state lasers. These lasers are bulky and relatively expensive, limiting their usage as bench-top systems in laboratory environments. Historically, semiconductor lasers, also known as laser diodes, have served applications where size and cost are important factors, including fiber optic communications. The linewidth of the semiconductor lasers, however, has been limited to the MHz-level, due to high loss in laser cavities and small size.</p> <p>Recently, reduction of the frequency fluctuations in the semiconductor lasers has been achieved, obtaining tens of kHz linewidth, using the heterogeneous Silicon/III-V platform with a new design strategy. In this design, the majority of the optical energy is stored in the low-loss high-Q silicon resonator away from the high-loss III-V active region, requiring the minimal gain from the active region to overcome the reduced modal loss.</p> <p>This work explores the new design strategy further, and demonstrates theoretically and experimentally that the strategy eliminates the frequency fluctuations arising from the amplitude-phase coupling by placing a relaxation resonance frequency at frequencies of a few hundred MHz. Consequently, it becomes possible to obtain a semiconductor laser device possessing sub-kHz quantum-limited linewidths at frequencies of a few GHz (the frequencies of interest in optical telecommunication).</p> <p>In addition to the frequency noise reduction, the strategy turns out to have the additional benefit of accomplishing a coherent and stable lasing operation, even under external reflections. Thus, the new design strategy has the potential to replace the costly, but currently indispensable external optical isolators, which have been traditionally used to maintain the consistent performance of semiconductor lasers in the presence of external reflection.</p> <p>This work paves the way for the design of narrow-linewidth and stable semiconductor lasers that can function without the use of the bulky and costly external components, such as external cavities or optical isolators.</p>
author Kim, Dongwan
spellingShingle Kim, Dongwan
Frequency Noise Control of Heterogeneous Si/III-V Lasers
author_facet Kim, Dongwan
author_sort Kim, Dongwan
title Frequency Noise Control of Heterogeneous Si/III-V Lasers
title_short Frequency Noise Control of Heterogeneous Si/III-V Lasers
title_full Frequency Noise Control of Heterogeneous Si/III-V Lasers
title_fullStr Frequency Noise Control of Heterogeneous Si/III-V Lasers
title_full_unstemmed Frequency Noise Control of Heterogeneous Si/III-V Lasers
title_sort frequency noise control of heterogeneous si/iii-v lasers
publishDate 2018
url https://thesis.library.caltech.edu/10540/13/Dongwan_thesis_2017_final_print.pdf
Kim, Dongwan (2018) Frequency Noise Control of Heterogeneous Si/III-V Lasers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z90Z71G6. https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721 <https://resolver.caltech.edu/CaltechTHESIS:10262017-003847721>
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