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:
Feb. 10, 1998
Filed:
Nov. 07, 1996
Junji Nishii, Ikeda, JP;
Hiroshi Yamanaka, Ikeda, JP;
Agency of Industrial Science & Technology, Tokyo, JP;
Abstract
This invention provides a method of producing a diffraction grating of a spectroscope by applying light to a thin film of glass having characteristics such that a density change occurs with the change of a glass structure upon irradiation of light and volume expansion occurs irreversibly. The method comprises applying light to a diffraction grating formation of a surface of the thin film by applying light through a phase mask or applying interference light, and causing the light irradiation portion of glass to expand and to thereby form the diffraction grating. Light to be applied is generally laser beams of ultraviolet rays, such as an excimer laser, a Nd-YAG laser or UV higher harmonics of a dye laser. A laser beam of a visible light region can be used, too. Preferably, a silica single crystal plate is used for the substrate of the thin film, and sputter vacuum deposition is used for forming the thin film. The glass composition whose volume expands upon irradiation of light is GeO.sub.2 --SiO.sub.2 type glass having a GeO.sub.2 content of 20 to 95 mol %, but this composition is not particularly limitative, and any glass compositions can be used so long as they have a high volume expansion coefficient.