Single-Mode Tunable Interband Cascade Laser Emitting at 3.4 μm With a Wide Tuning Range Over 100 nm

We report a widely tunable monolithically integrated V-coupled cavity interband cascade laser (ICL) emitting near
$3.4~\mu \text{m}$
. The mode selection is achieved using a half-wave V-coupler designed for the ICL in the mid-infrared range without any grating. The side-mode suppression ratio is demonstrated up to 35.7 dB. In the heat-sink temperature range from 130 K to 140 K, single-mode wavelength tuning range of over 100 nm from 3329.9 nm to 3431.3 nm has been attained by adjusting both current and temperature. These results show that the V-coupled cavity ICLs are very promising for multi-species trace gas absorption spectroscopy with a high sensitivity.