The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 2022
Filed:
Apr. 24, 2019
Hitachi High-tech Corporation, Tokyo, JP;
Takanori Aono, Tokyo, JP;
Yoshisada Ebata, Tokyo, JP;
Kenta Yaegashi, Tokyo, JP;
Shigeru Matsui, Tokyo, JP;
HITACHI HIGH-TECH CORPORATION, Tokyo, JP;
Abstract
The present invention provides a concave diffraction grating capable of improved diffraction efficiency by suppressing spherical aberration. The concave diffraction grating is a concave diffraction gratingfor dispersing and focusing light and comprises sawtooth grating grooveson a concave substrate, with the sawtooth grating groovesbeing unequally spaced. The concave diffraction gratingfor dispersing and focusing light is formed by preparing a planar diffraction grating with a sawtooth shape which is formed on a planar substrate by photo-lithography and etching or machining and which forms unequally spaced grating grooves, deforming and mounting the planar diffraction grating along a fixed convex substrate to obtain a mold of a concave diffraction grating, and transferring the mold of the concave diffraction grating to the surface of a metal or a resin.