Milliwatt second harmonic generation in quantum cascade lasers with modal phase matching

Milliwatt second harmonic power at 4.45 mum was achieved in InP lattice-matched quantum cascade lasers with monolithically-integrated resonant nonlinear cascades and modal phase matching. The use of an InP top-cladding layer and high-reflectance coating on the laser back facet enabled high linear laser power and consequently record nonlinear power.