Liquid crystal diffraction element and optical device

A liquid crystal diffraction element comprising a cholesteric liquid crystal layer,

• wherein the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating along at least one direction in-plane, and
• the cholesteric liquid crystal layer has a region where, in a case where retardation is measured from a normal direction of a main surface of the cholesteric liquid crystal layer and from a direction inclined with respect to a normal line, a direction in which the retardation is minimum is inclined with respect to the normal direction, and a region where the direction in which the retardation is minimum differs in-plane.