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. 16, 1987
Filed:
Oct. 10, 1985
Applicant:
Inventors:
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Primary Examiner:
Int. Cl.
CPC ...
G03H / ; G02B / ;
U.S. Cl.
CPC ...
350-364 ; 350 9614 ; 350 9634 ;
Abstract
An optical branching filter element comprised of a substrate having a wave guide thereon of a material capable of reversibly changing its refractive index and an erasable diffraction grating formed on the waveguide. The diffraction grating may be formed by a holographic exposure method or a light beam scanning method and may be erased by suitable erasing means.