Bragg diffraction of light by rectangular phase gratings

Bragg diffraction of light by rectangular phase gratings is considered, utilizing two-dimensional coupled-wave theory. Diffraction characteristics for two important cases of incident plane waves and Gaussian-profile beams are presented. It is shown that the diffraction properties depend on the following normalized parameters: the grating strength and a geometry parameter, the beam width and a displacement. Values of these parameters for the realization of both nearly transmitting and nearly reflecting regimes of diffraction are determined. The results obtained are used for the choice of the design parameters of integrated optic Bragg-type devices.