Above-room-temperature optically pumped 4.12 μm midinfrared vertical-cavity surface-emitting lasers

Optically pumped lead salt vertical-cavity surface-emitting lasers (VCSELs) with a nine period PbSe/PbSrSe quantum well active region operating above room temperature in pulsed mode are reported. The gain peak and cavity mode of the VCSEL structure are in resonance at 300 K. A power output of 40 mW is obtained at room temperature and it does not show saturation. The room-temperature threshold pump density is 200 kW/cm2. The lasing wavelength of λ=4.12 μm remains nearly constant over a temperature range of 280–310 K.