Method and design method of transmission diffraction grating, optical waveguide and transmission diffraction grating

摘要

A transmission-type diffraction grating provided with a serrated first surface including first inclined surfaces and second inclined surfaces, and a flat second surface. A light beam incident on the first inclined surfaces of the first surface at a predetermined incidence angle is reflected by the second inclined surfaces and emitted from the second surface. The predetermined incidence angle is preferably 20°-80°. The incidence angle and the diffraction angle are preferably equal.