Pulsed-squeezed-light generation in a waveguide with second-subharmonic generation and periodic corrugation

Quantum pulsed second-subharmonic generation in a planar waveguide with a small periodic corrugation at the surface is studied. Backscattering of the interacting fields on the corrugation enhances the nonlinear interaction, giving larger values of squeezing. The problem of backscattering is treated by perturbation theory, using the Fourier transform for nondispersion propagation, and by numerical approach in the general case. Optimum spectral modes for squeezed-light generation are found using the Bloch-Messiah reduction. An improvement in squeezing and increase of the numbers of generated photons are quantified for the corrugation resonating with the fundamental and second-subharmonic field. Splitting of the generated pulse by the corrugation is predicted. DOI: 10.1103/PhysRevA.87.013833