Second harmonic generation in (111)-oriented InP-based quantum cascade laser

We show the realization of quantum cascade lasers (QCL) grown on (111)-oriented InP substrates instead of the usual (100)-oriented surface. Growth along [111] orientation allows the excitation of the nonlinear susceptibility for the transverse magnetic wave produced by the QCL. Two devices were realized, at 6 and 10 μm wavelengths. They are compared with the same structures grown on the usual (100)-oriented surface. Second harmonic generation is demonstrated in one of the devices.