Periodically corrugated nonlinear planar waveguide as a source of squeezed light

A photonic band-gap structure (a small periodic corrugation at the surface) present in a planar nonlinear waveguide can enhance the nonlinear process of second-subharmonic generation provided that all interactions are phase matched. Compared with a perfectly quasi-phase matched waveguide, better values of squeezing and higher intensities of the output fields are reached under these conditions.