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:
Jul. 25, 1995
Filed:
Aug. 02, 1994
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
An optical waveguide device for coupling an external wave with a guided wave by means of a grating coupler formed on an optical waveguide device which lies on a substrate. The grating coupler is further coated with a cladding layer. An external wave is transformed into a guided wave after being diffracted by a first grating coupler, and travels along the waveguide to a second grating coupler. The guided wave is then subjected to diffraction by means of the second grating coupler, whereupon a minus first-order wave is diffracted only toward the substrate, whilst other waves of higher order are respectively diffracted toward the cladding layer and the substrate. The wave diffracted toward the cladding layer is totally reflected from a cladding layer boundary furtherst from the substrate, thereby passing through the substrate. The diffracted wave thus reflected interferes with the other wave of the same order diffracted to the substrate, thereby weakening each other.