Low fabrication cost wavelength tunable WG-FP hybrid-cavity laser working over 1.7 μm

Abstract A wide wavelength tuning range and single-mode hybrid cavity laser consists of a square Whispering-Gallery (WG) microcavity and a Fabry–Pérot (FP) was introduced and demonstrated. A wavelength tuning range over 12.5 nm from 1760.87 to 1773.39 nm which was single-mode emitting was obtained with the side-mode suppression ratio over 30 dB. The hybrid cavity laser does not need grating etching and special epitaxial structure, which reduces the fabrication difficulty and cost, and shows the potential for gas sensing with absorption lines in this range.