High average power uncooled mid-wave infrared quantum cascade lasers

High-performance uncooled quantum cascade lasers emitting at wavelengths of 4.6 and 4.0 µm are reported. The 4.6 µm lasers show an average optical power in excess of 2 W at a heatsink temperature of 300K, wall-plug efficiencies of 13 and 10% at output power levels of 1 and 2 W, respectively, and an average power in excess of 1.2 W at 340K. The 4.0 µm lasers show an average optical power in excess of 1.5 W at 300K and wall-plug efficiencies of 9 and 7% at output power levels of 1 and 1.5 W, respectively.