公开(公告)号：US20230079523A1

公开(公告)日：2023-03-16

申请号：US17798228

申请日：2021-01-14

Applicant: Hitachi High-Tech Corporation

Inventor： Takanori AONO ,  Yoshisada EBATA ,  Kenta YAEGASHI ,  Shigeru MATSUI ,  Isao UCHIDA ,  Jiro YAMAMOTO

IPC: G02B5/18

Abstract: The present invention provides a concave diffraction grating and an optical device using the concave diffraction grating, the concave diffraction grating being capable of preventing deformation of a reflection film due to the influence of temperature, and preventing deterioration in optical characteristic due to temperature. This concave diffraction grating is provided with: a reflection film (22) having a plurality of grating grooves (21); a holding film (25) comprising metal and having one surface on which the reflection film (22) is provided; a concave substrate (24) having a concave surface (24a); and an affixing layer (23) provided between the concave surface (24a) and the other surface of the holding film (25), and affixing the holding film (25) and the reflection film (22) to the concave substrate (24).