Method for manufacturing optical element, optical element and display device

A method for manufacturing an optical element, comprising

• a first step of performing, after affixing a first hologram forming material to a glass substrate having a marking portion, interference exposure on the first hologram forming material, thereby forming a first hologram layer at the glass substrate;
• a second step of performing, after affixing a second hologram forming material to the first hologram layer, interference exposure on the second hologram forming material, thereby forming a second hologram layer at the first hologram layer;
• and
• a third step of affixing a laminated body of the first hologram layer and the second hologram layer, peeled off from the glass substrate, to a plastic substrate having a first alignment mark, wherein
• the third step includes using the first alignment mark on the plastic substrate, and at least one of a second alignment mark formed at a position corresponding to the marking portion in the first hologram layer in the first step and a third alignment mark formed at a position corresponding to the marking portion in the second hologram layer in the second step to implement positioning of the plastic substrate and the laminated body.