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. 17, 2003
Filed:
Dec. 21, 2001
Toshimi Kominato, Ibaraki, JP;
Akio Sugita, Ibaraki, JP;
Mikitaka Itoh, Ibaraki, JP;
Yasuyuki Inoue, Ibaraki, JP;
Yasuhiro Hida, Ibaraki, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
An optical waveguide circuit is provided that can reduce or eliminate polarization dependence by reducing or eliminating birefringence. A substrate consists of a silicon substrate, and a cladding and a core are composed of silica-based glass. The core has a multilayer structure composed of a few types of layers with different refractive indices such as first core layers and second core layers stacked in the direction parallel to the substrate. As for the birefringence of the waveguide, the geometrical birefringence caused by the multilayer structure is canceled out by the other birefringence, thereby being able to reduce or eliminate the birefringence of the waveguide.