SEGMENT GRATING ALIGNMENT DEVICE

摘要

A grating alignment device performs alignment of two or more plane gratings so as to eliminate an angular misalignment and a phase misalignment which are caused between respective diffracted light beams generated when incident light is diffracted by the plane gratings. Specifically, alignment is performed by appropriately adjusting an angle A, an angle B, an angle C, a coordinate Z, and a coordinate X of the second plane grating so as to eliminate at least one of the angular misalignment and the phase misalignment which are caused between the respective diffracted light beams generated when incident light is diffracted by the first plane grating and the second plane grating.