Unified approach to Cerenkov second harmonic generation

We discuss the effect of second harmonic generation via the Cerenkov-like process in nonlinear bulk media and waveguides. We show that in both schemes the Cerenkov harmonic emission represents in fact a nonlinear Bragg diffraction process. It is therefore possible, for the first time, to describe the bulk and waveguide Cerenkov emission uniformly by considering the spatial modulation of the second-order nonlinear polarization. This is also experimentally illustrated by studying the Cerenkov second harmonic generation at the boundary of a nonlinear quadratic medium via the total internal reflection inside the nonlinear crystal. (c) 2013 Optical Society of America