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:
Nov. 08, 1994
Filed:
May. 24, 1993
Yasuhiro Akune, Sanda, JP;
Kichiya Tanino, Sanda, JP;
Masaru Koeda, Kyoto, JP;
Tetsuya Nagano, Kyoto, JP;
Kazuo Sano, Kyoto, JP;
Eiji Ishiguro, Nara, JP;
Nippon Packing Co., Ltd., Osaka, JP;
Shimadzu Corporation, Kyoto, JP;
Abstract
The present invention discloses diffraction gratings which do not generate any thermal strain and can perform extremely high-precision and high-efficiency diffraction nearly free from scattered beams. The diffraction gratings are built by allowing the chemically deposited film of silicon carbide whose crystal planes are strongly oriented to the (220) planes in terms of Miller indices to form on the substrate comprising sintered silicon carbide, polishing the surface of the deposited film to 5 .ANG. RMS or less, and directly etched laminar-type grating grooves on that surface by using ion-beam etching.