Continuous-wave (CW) operation of a mid-infrared type-II interband cascade
(IQ laser has been demonstrated at temperatures up to 142 K by improving de
vice processing and fabrication. Also, the IC laser exhibited record-high w
all-plug efficiencies (similar to 18 % at 60 K) with considerable CW output
powers. An analysis of the thermal resistance partially explains the still
low maximum CW operating temperature and suggests further potential for im
provement with continued development of fabrication/packaging techniques.