Type-II interband cascade lasers in the 4.3-4.7-μm wavelength region

Operation of type-II interband cascade lasers in the 4.3-4.7-μm wavelength region has been demonstrated at temperatures up to 240 K in pulsed mode. These lasers fabricated with 150-μm-wide mesa stripes operated in continuous-wave (CW) mode up to a maximum temperature of 110 K, with an output power exceeding 30 mW/f and a threshold current density of about 41 A/cm
²
at 90 K. The maximum CW operation temperature of 110 K is largely limited by the high specific thermal resistance of the 150-μm-wide broad area lasers. A 20-μm-wide mesa stripe laser was able to operate in CW mode at higher temperatures up to 125 K as a result of the reduced specific thermal resistance of a smaller device.