Second-Harmonic Generation in Quantum Cascade Lasers with Electric Field and Current Dependent Nonlinear Susceptibility
15 January 2007
We demonstrate a quantum cascade laser design with an integrated resonant nonlinearity for second-harmonic generation. Its nonlinear power conversion efficiency is strongly dependent on the injected current density, due to an electric eld and current dependent nonlinear susceptibil ity. This dependence produces an observed ten-fold increase of the conversion efficiency over the current density range of 2:7 to 7:5 kA/cm2 . Furthermore, bidirectional lasing at widely different wavelengths is a side-effect for this active region design.