High-performance mid-infrared type-II interband cascade lasers have been de
monstrated under continuous-wave (CW) conditions with record-high wall-plug
efficiencies (>14%) and output powers (>100 mW/facet) above 77 K, Device c
haracteristics of these type-II interband cascade lasers are investigated s
ystematically in terms of their output powers and efficiencies. Also, by co
mparing the temperature dependence of the threshold currents under pulsed a
nd CW conditions, the thermal resistance and maximum heat sink temperature
for CW operation are estimated for several mesa sizes. The limiting factors
due to device heating for high-power/high-efficiency operation are identif
ied and discussed in connection with device dimensions and packaging for th
e purpose of assessing further improvements.