High peak power λ∼3.3 and 3.5 μm InGaAs/AlAs(Sb) quantum cascade lasers operating up to 400 K

We demonstrate lambda similar to 3.5 mu m and lambda similar to 3.3 mu m strain compensated In(0.7)Ga(0.3)As/AlAs(Sb)/InP quantum cascade lasers operating in pulse regime at temperatures up to at least 400 K. Peak optical power exceeding 3.5 W at 300 K has been achieved at both wavelengths for 10 mu m wide 4 mm long lasers with high reflectivity coated back facets. Threshold current densities of 2.5 kA/cm(2) and 3.5 kA/cm(2) have been observed at 300 K for the devices emitting at lambda similar to 3.5 mu m and lambda similar to 3.3 mu m, respectively. (C) 2010 American Institute of Physics. [doi:10.1063/1.3464551]