Optical element

An optical element comprising:

• a substrate;
• and
• a laminate that is provided on the substrate and where a plurality of liquid crystal layers obtained by aligning a liquid crystal compound are laminated,
• wherein the liquid crystal layers forming the laminate have a liquid crystal alignment pattern in which a direction of an optical axis derived from the liquid crystal compound changes while continuously rotating in at least one in-plane direction,
• at least one of the liquid crystal layers forming the laminate satisfy the following film thickness distribution requirement, and
• the liquid crystal layers forming the laminate are cholesteric liquid crystal layers obtained by immobilizing a cholesteric liquid crystalline phase, and selectively reflect visible light,
• wherein the laminate comprises the liquid crystal layers, each of which selectively reflects light of a different wavelength, and
• wherein a permutation of wavelengths of the light to be selectively reflected by each of the liquid crystal layers and a permutation of lengths of one period of the liquid crystal alignment pattern in the liquid crystal layers match each other,
• film thickness distribution requirement
• a cross-section of the liquid crystal layer in a thickness direction is observed with a scanning electron microscope at a magnification of 10000-fold while continuously moving an observation position in an in-plane direction of the liquid crystal layer to perform an operation in which 20 images in a range of 200 μm in the in-plane direction of the liquid crystal layer are acquired to acquire a difference between a maximum film thickness and a minimum film thickness in the range of 200 μm in the in-plane direction of the liquid crystal layer, and in a case where this operation is performed on any 10 cross-sections of the liquid crystal layer, an arithmetic mean value of the acquired differences between the maximum film thicknesses and the minimum film thicknesses in the 10 cross-sections is 0.1 μm or less.