Single-mode distributed-feedback interband cascade laser for the midwave infrared.

Continuous-wave single-mode emission near λ=3.42 μm is obtained from a distributed-feedback (DFB) interband cascade laser. The low-loss DFB mode in the 15-μm-wide ridge is resonant with the gain peak at 110 K, where the maximum single-mode output power is 3 mW. The instrument-limited linewidth is ≤=0.5 Å, and the wavelength is linearly tunable over a 4 nm range by varying the temperature from 110 to 125 K (0.28 nm/K), or over 0.6 nm by varying the current from 60 to 83 mA (0.031 nm/mA) [ABSTRACT FROM AUTHOR]