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.

Original languageEnglish
Article number9205996
Pages (from-to)105-111
Number of pages7
JournalJournal of Lightwave Technology
Issue number1
Early online date25 Sep 2020
Publication statusPublished - 1 Jan 2021

    Research areas

  • Optical feedback, optical frequency combs, semiconductor lasers

ID: 4218421