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. 22, 2005
Filed:
Sep. 27, 2002
Keisuke Ikeda, Shizuoka, JP;
Shohei Abe, Shizuoka, JP;
Isao Kojima, Aichi, JP;
Yuko Ota, Shizuoka, JP;
Ikuo Maeda, Shizuoka, JP;
Keisuke Ikeda, Shizuoka, JP;
Shohei Abe, Shizuoka, JP;
Isao Kojima, Aichi, JP;
Yuko Ota, Shizuoka, JP;
Ikuo Maeda, Shizuoka, JP;
FDK Corporation, Tokyo, JP;
Abstract
A variable optical attenuator is disclosed which comprises a plane-parallel birefringent element for separation/synthesis which separates light beams having orthogonal polarization directions on the same optical path, the birefringent element synthesizing light beams on different optical paths; a light converging lens disposed adjacent to the birefringent element for separation/synthesis; a reflecting mirror disposed at a focal point of the lens opposite to the birefringent element for separation/synthesis with respect to the lens; a variable polarization rotating device; and an input port and an output port which are disposed at the end of the birefringent element for separation/synthesis; the variable polarization rotating device being disposed at any position between the birefringent element for separation/synthesis and the reflecting mirror, the variable polarization rotating device controlling the rotational angle of the polarization direction of incident light beams from the input port, to thereby control the amount of reflected output light to the output port.