High-performance quantum cascade lasers (lambda similar to 11 mu m) operating at high temperature (T >= 425 K)

We report record-low threshold current density and high output power for la mbda similar to 11 mum Al0.48In0.52As/Ga0.47In0.53As quantum cascade lasers operating up to 425 K. The threshold current density is 1.1, 3.83, and 7.0 8 kA/cm(2) at 80, 300, and 425 K, respectively, for 5 mus pulses at a 200 H z repetition rate. The cavity length is 3 mm with a stripe width of 20 mum. The maximum peak output power per facet is 1 W at 80 K, 0.5 W at 300 K, an d more than 75 mW at 425 K. The characteristic temperature of these lasers is 174 K between 80 and 300 K and 218 K in the range of 300-425 K. (C) 2001 American Institute of Physics.