Intracavity second harmonic generation in quantum cascade lasers in the telecommunication range

Abstract

We propose and theoretically study the performance of short-wavelength mid-infrared quantum cascade lasers integrated with resonant second-harmonic generation (SHG) cascade. We show the feasibility of SHG in the near infrared range 1.5-2 μm with nonlinear susceptibility of ~150 pm/V. Theoretical treatment takes into account the non-sphericity and the non-parabolicity of the conduction band within a modified energy-dependent effective mass approximation based on the 14 band kP model. This approximation is shown to coincide with the first conduction band calculated by the 30 band kP model up to 2.3 eV above the band edge. We demonstrate the possibility of modal phase matching in the InGaAs/AlAsSb/InP QC laser which yields the intracavity frequency conversion efficiency of the order of 0.2 mW/W 2 .