Single-longitudinal-mode emission from interband cascade DFB laser with a grating fabricated by interferometric lithography

A distributed-feedback, type-II interband cascade laser is demonstrated in pulsed mode, emitting near 3.145 (mu)m at temperatures between 50 and 80 K. Feedback is provided by a surface-etched grating formed using interferometric lithography. Between 50 and 80 K, the deviceʹs single longitudinal mode red-shifts with temperature at ~0.1 nm/K. At 70 K and 190 mA of pulsed injection current, side-mode suppression exceeds 30 dB. The characteristics of related Fabry-Perot IC lasers are also described and contrasted with those of the distributed feedback device.