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arXiv · 2607.24240

Ultranarrow-linewidth self-injection-locked tunable blue GaN DFB laser

Georges Perin·Laurent Lablonde·Marco Rossetti·Marco Malinverni·Antonino Castliglia·Marcus Duelk·Stéphane Trebaol
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Abstract

In this work, we demonstrate an ultra-narrow linewidth self-injection locked distributed feedback (DFB) diode laser emitting at 452 nm, achieving an intrinsic linewidth of 170 Hz with a fiber output power of 11 mW. The linewidth reduction of the DFB laser is obtained thanks to the coupling with an external cavity based on a fiber Bragg grating (FBG). Experimental results demonstrate excellent agreement with our theoretical modeling of the self-injection dynamics. Furthermore, the tuning capabilities of the system are characterized, with tunability achieved via current modulation, yielding a tuning efficiency of 300 MHz/mA over a continuous mode-hop-free range of 600 MHz. This architecture offers a robust pathway toward an integration within a compact package. Ultimately, such compact, stable, and frequency-tunable visible light sources are key for integrated optical atomic clocks and underwater lidar application.

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Georges Perin, Laurent Lablonde, Marco Rossetti, Marco Malinverni, Antonino Castliglia, Marcus Duelk, Stéphane Trebaol. 2026-07-27. Ultranarrow-linewidth self-injection-locked tunable blue GaN DFB laser. https://arxiv.org/abs/2607.24240

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