Microsized optical parametric oscillator in photonic crystals

Optical parametric oscillators (OPO) in bulk media have been used as tunable light sources for a long time. In recent years micro-optical realizations of OPOs were also subject of interest. Here a short quadratically nonlinear crystal is reflection coated on two sides to provide the feedback of a Fabry-Perot cavity. Depending on the coating, both, the pump and the signal wave, can be resonant or just one of them.