Optical element, wavelength selective filter, and sensor

Abstract

Provided are an optical element with which reflected light in a narrower wavelength range can be obtained and a wavelength selective filter and a sensor including the same optical element. The optical element includes a cholesteric liquid crystal layer obtained by cholesteric alignment of a liquid crystal compound, in which the cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, and the cholesteric liquid crystal layer has a region where a refractive index nx in an in-plane slow axis direction and a refractive index ny in an in-plane fast axis direction satisfy nx>ny.

Dependencies are inferred from the claim text.