@article{131dbc8fda504b8180614e7f26316262,
title = "Linewidth Sharpening in Optical Frequency Combs via a Gain Switched Semiconductor Laser with External Optical Feedback",
abstract = "In this article, we propose a novel scheme for an optical frequency comb (OFC) generator which implements a gain switched (GS) semiconductor laser (SL) in the presence of external optical feedback (EOF). Numerical results demonstrate that with appropriate choices of the basic system parameters (i.e., the feedback coupling fraction, the laser bias current and the external cavity length), the linewidths in the OFCs generated by the GS SL with EOF can be significantly reduced below that of the free running continuous wave (CW) SL. Such a significant linewidth reduction can be described by a simple analytic expression presented in this article which is found to be in good agreement with the numerical results.",
keywords = "Optical feedback, optical frequency combs, semiconductor lasers",
author = "Yuanlong Fan and Kang Li and Pu Li and Bethan Copner and Nigel Copner",
note = "Funding Information: Manuscript received July 21, 2020; revised September 1, 2020; accepted September 23, 2020. Date of publication September 25, 2020; date of current version January 2, 2021. This work was supported in part by National Natural Science Foundation of China under Grant 61775158; and in part by China Postdoctoral Science Foundation under Grant 2018M630283 and Grant 2019T120197. (Corresponding author: Yuanlong Fan.) Yuanlong Fan, Kang Li, Bethan Copner, and Nigel Joseph Copner are with the Wireless & Optoelectronics Research & Innovation Centre, School of Engineering, University of South Wales, Treforest CF37 1DL, U.K. (e-mail: yuanlong.fan@southwales.ac.uk; kang.li@southwales.ac.uk; bethan.copner@southwales.ac.uk; nigel.copner@southwales.ac.uk). Publisher Copyright: {\textcopyright} 1983-2012 IEEE. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",
year = "2021",
month = jan,
day = "1",
doi = "10.1109/JLT.2020.3026722",
language = "English",
volume = "39",
pages = "105--111",
journal = "Journal of Lightwave Technology",
issn = "0733-8724",
publisher = "Institute of Electrical and Electronics Engineers",
number = "1",
}