The diffraction of light on the corrugated surface of a layered structure w
as investigated. It was shown that the excitation of waveguide modes in the
layered structure alters significantly the diffraction efficiency of the c
orrugated structure. It was found that in the autocollimation regime the di
ffraction efficiency of the grating can reach 100% for moderate depths of t
he grating grooves. The suitability of a waveguide-grating mirror in dye la
sers was demonstrated experimentally.