Autocollimation reflection of light from the surface of corrugated waveguides with leaky modes

The diffraction of light at the corrugated surface of a layer structure was studied. We show that the excitation of the waveguide modes in a layer structure causes a significant change in the diffraction efficiency of the corrugated structure. It is found that the diffraction efficiency of a grating in the autocollimation regime may be as much as 100% with reasonable depths of the grating. The efficiency of a waveguide-grating mirror in dye lasers is experimentally demonstrated.