25 kHz narrow spectral bandwidth of a wavelength tunable diode laser with a short waveguide-based external cavity

TL;DR

This paper presents a compact, tunable diode laser with an exceptionally narrow spectral bandwidth of 25 kHz, capable of rapid wavelength switching across the telecom C-band with high side-mode suppression.

Contribution

It demonstrates a short waveguide-based external cavity diode laser achieving ultra-narrow spectral bandwidth and fast tuning over the entire telecom C-band.

Findings

Spectral bandwidth as small as 25 kHz (FWHM)

Tuning over the full telecom C-band (1530-1565 nm)

Wavelength access in as little as 200 microseconds

Abstract

We report on the spectral properties of a diode laser with a tunable external cavity in integrated optics. Even though the external cavity is short compared to other small-bandwidth external cavity lasers, the spectral bandwidth of this tunable laser is as small as 25 kHz (FWHM), at a side-mode suppression ratio (SMSR) of 50 dB. Our laser is also able to access preset wavelengths in as little as 200 us and able to tune over the full telecom C-band (1530 nm - 1565 nm).