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. 27, 2008
Filed:
Jul. 30, 2007
Teruhisa Nakamura, Shizuoka, JP;
Hidenori Nakata, Aichi, JP;
Kenji Sahara, Shizuoka, JP;
Yuko Ohta, Shizuoka, JP;
Teruhisa Nakamura, Shizuoka, JP;
Hidenori Nakata, Aichi, JP;
Kenji Sahara, Shizuoka, JP;
Yuko Ohta, Shizuoka, JP;
FDK Corporation, Tokyo, JP;
Abstract
A variable optical attenuator comprising a separation/combination birefringent element, fixed polarization rotation means, a convex lens, variable polarization rotation means, and a mirror which are arranged in that order. The fixed polarization rotation means has a compensation film Faraday element placed in a cylindrical permanent magnet, and the variable polarization rotation means has a base film Faraday element that is placed outside the cylindrical permanent magnet, and an electromagnet applying a variable magnetic field thereto. Thereby, both the Faraday elements are magnetized in directions different from each other.