Optically- and electrically-pumped type-II "W" quantum well lasers for the mid IR

Description

This item was taken from the IEEE Conference ' Optically- and electrically-pumped type-II "W" quantum well lasers for the mid IR ' Optically pumped mid-IR lasers with type-II "W" active regions (InAs-GaInSb-InAs-AlAsSb) recently lased cw at temperatures up to 290 K at /spl lambda/=3.0 /spl mu/m and to 135 K at 7.1 /spl mu/m. The cw output power exceeded 0.5 W at 78 K and /spl lambda/=3.2 /spl mu/m. However, conversion efficiencies must be improved if the ultimate goal of high cw power at thermoelectric-cooler temperatures is to be achieved. Here we report encouraging progress toward that objective using the optical-pumping injection cavity (OPIC) approach, in which the active region is enclosed in an etalon cavity whose resonance is tuned to the pump wavelength, /spl lambda//sub pump/. Experiments on MBE-grown structures containing semiconductor Bragg mirrors above and below the active quantum wells (QWs) confirm that the multiple passes of the pump result in (1) enhanced pump-beam absorptance, (2) reduced threshold, and (3) reduced internal loss.