Room temperature continuous wave operation of λ ∼ 3-3.2 μm quantum cascade lasers

We demonstrate quantum cascade lasers emitting at wavelengths of 3-3.2 mu m in the InP-based material system. The laser core consists of GaInAs/AlInAs using strain balancing technique. In room temperature pulsed mode operation, threshold current densities of 1.66 kA/cm(2) and 1.97 kA/cm(2), and characteristic temperatures (T-0) of 108K and 102 K, are obtained for the devices emitting at 3.2 mu m and 3 mu m, respectively. Room temperature continuous wave operation is achieved at both wavelengths. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769038]