Analytical characteristics of the CSHG in a channel waveguide

Based on the coupled-mode theory, Cherenkov second harmonic generation (CSHG) from a channel waveguide has been analyzed and discussed in detail. The conversion efficiency with only conversion depletion and the conversion efficiency with conversion depletion and propagation loss are obtained respectively, the results show that for the case of low conversion efficiency the conversion depletion can be neglected, but for the case of high conversion efficiency we Must take conversion depletion into account,, and the propagation loss Must be taken into accounted for the both. Furthermore, the nonlinear phase shift (NPS) of the fundamental beam can be maximized by choosing appropriate grating period and appropriate waveguide thickness, which makes the configuration have a promising potential to realize all-optical switches.