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:
Mar. 13, 2001
Filed:
Aug. 27, 1999
Applicant:
Inventors:
Masaaki Kurihara, Tokyo, JP;
Toshikazu Segawa, Tokyo, JP;
Assignee:
Dai Nippon Printing Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03F 9/00 ;
U.S. Cl.
CPC ...
G03F 9/00 ;
Abstract
The invention relates to a diffraction grating-forming phase mask which can make the diffraction grating to be formed substantially free of any defect, even when foreign matters or resins, etc. sublimed from an optical fiber are deposited on the surface of the phase mask. The phase mask,comprises a substrate and a grating form of repetitive groove (,)-and-strip (,) pattern for forming a diffraction grating by interference fringes of diffracted light through the repetitive pattern. An optically transparent protective layer,is applied over the surface of the substrate with the repetitive groove (,)-and-strip (,) pattern formed thereon.