High power and narrow linewidth semiconductor lasers for atomic clock

Di Gaetano, Eugenio (2019) High power and narrow linewidth semiconductor lasers for atomic clock. PhD thesis, University of Glasgow.

Abstract

The compactness, low energy consumption and potential for volume production typical of semiconductor technology are key requirements for future miniaturised quantum systems. This thesis - funded by the Defence and Security Call 2014 on Sensing and Navigation using quantum 2.0 technologies - discusses the development of III-V semiconductor Distributed FeedBack (DFB) lasers for atomic clock systems. Specifically, the work targets devices for atomic cooling emitting at wavelengths that match the atomic transitions of cesium Cs and rubidium Rb at the wavelength of 852nm and 780nm (i.e. frequency doubled from 1560nm), and with the required performance in terms of linewidth (100kHz) and power output (100mW). These objectives were reached by working on different fronts: i) the optimization of the fabrication process to improve the robustness and repeatability of the manufacturing process, with particular emphasis on the dry etching process to ensure vertical and smooth surfaces; ii) the development of a strongly-coupled Bragg grating geometry that mitigates the detrimental impact of the so-called Reactive Ion Etching (RIE) lag; iii) the demonstration of a novel coupling chirp grating design to improve the intra-cavity field uniformity and improve the laser stability. Thanks to these design strategies and technological solutions the performance requirements in terms of output powers and linewidth were met on DFB lasers emitting at a wavelength of 1560nm. These same concepts are currently being transferred on devices fabricated on an epilayer structure emitting at 852nm.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Due to copyright issues this thesis is not available for viewing. The print version is available for consultation once any embargo period has expired.
• Keywords: Semiconductor Lasers, Narrow linewidth, DFB lasers, atomic clock, Bragg gratings.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• Colleges/Schools: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Funder's Name: Defence Science and Technology Laboratory (DSTL)
• Supervisor's Name: Sorel, Prof. Marc
• Date of Award: 2019
• Embargo Date: 7 June 2022
• Depositing User: Mr Eugenio Di Gaetano
• Unique ID: glathesis:2019-73048
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 13 Jun 2019 08:04
• Last Modified: 05 Mar 2020 22:26
• Thesis DOI: 10.5525/gla.thesis.73048
• URI: http://theses.gla.ac.uk/id/eprint/73048

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