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:
May. 18, 1999
Filed:
Feb. 28, 1997
Toshihiro Shintaku, Ibaragiken, JP;
Yujiro Katoh, Ibaragiken, JP;
Yoshiaki Tachikawa, Tokyo, JP;
Naoto Sugimoto, Ibarakiken, JP;
Haruki Kozawaguchi, Tokyo, JP;
Abstract
An inexpensive polarization independent optical nonreciprocal circuit which does not require a use of expensive birefringent crystals, optical branching circuits, and a phase adjustment. The optical nonreciprocal circuit is formed by at least one lens through which a light propagating between two waveguides passes; and a polarization rotation circuit for sequentially applying a nonreciprocal rotation and a reciprocal rotation to a first half of the light propagating between two waveguides, and sequentially applying a reciprocal rotation and a nonreciprocal rotation to a second half of the light propagating between two waveguides, so that the first half and the second half of a light propagating forward are set to have an identical polarization to form an even guided mode and coupled, while the first half and the second half for a light propagating backward are set to have opposite polarizations to form an odd non-guided mode and dissipated.