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External optical feedback engineered to reduce and stabilize the linewidth of diode lasers

Research output: Contribution to book/anthology/report/proceedingArticle in proceedingsResearchpeer-review


Narrow-linewidth lasers are building blocks of coherent communication systems, as lower linewidths enable higherorder modulation formats with lower bit-error rates. For this purpose, diode lasers are in high demand due to their low power consumption, compactness, and potential for mass production. In field-testing scenarios, their output is coupled to a fiber, making them susceptible to external optical feedback (EOF), which is notoriously detrimental to their stability. This challenge is traditionally combated by using, for example, angled output waveguides and optical isolators. The approach reported in this work makes use of EOF in a new way, to reduce and stabilize the laser linewidth. Whereas research in this field has focused on EOF applied to only one side of the laser cavity, this work gives a generalization to the case of feedback on both sides. It is implemented using photonic components available via generic foundry platforms, thus creating a path towards devices with high technology-readiness level. It is numerically observed that the double-feedback case can lead to improved performance with respect to the single-feedback case. In particular, by correctly tuning the phase of the feedback from both sides, a broad region of stability is discovered. This work paves the way towards low-cost, integrated and stable narrow-linewidth integrated lasers.

Original languageEnglish
Title of host publicationLaser Resonators, Microresonators, and Beam Control XXIV
EditorsVladimir S. Ilchenko, Andrea M. Armani, Julia V. Sheldakova
PublisherSPIE - International Society for Optical Engineering
Publication yearMar 2022
Article number119870D
ISBN (Electronic)9781510648456
Publication statusPublished - Mar 2022
EventLaser Resonators, Microresonators, and Beam Control XXIV 2022 - Virtual, Online
Duration: 20 Feb 202224 Feb 2022


ConferenceLaser Resonators, Microresonators, and Beam Control XXIV 2022
ByVirtual, Online
SponsorThe Society of Photo-Optical Instrumentation Engineers (SPIE)
SeriesProceedings of SPIE - The International Society for Optical Engineering

Bibliographical note

Publisher Copyright:
© 2022 SPIE.

    Research areas

  • laser dynamics, laser stability, narrow-linewidth lasers, optical feedback, semiconductor lasers

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