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:
Oct. 07, 2014
Filed:
Jun. 27, 2011
Hiroaki Ono, Tokyo, JP;
Hidenori Nakada, Tokyo, JP;
Hirotaka Kawai, Tokyo, JP;
Yuko Ota, Tokyo, JP;
Taro Nakamura, Tokyo, JP;
Hiroaki Ono, Tokyo, JP;
Hidenori Nakada, Tokyo, JP;
Hirotaka Kawai, Tokyo, JP;
Yuko Ota, Tokyo, JP;
Taro Nakamura, Tokyo, JP;
FDK Corporation, Tokyo, JP;
Abstract
An input/output port, a birefringent element, variable polarization rotator, and a reflector are arranged along an optical axis in the order named. The variable polarization rotator includes permanent magnets for applying a fixed magnetic field to a Faraday rotator in an in-plane direction to magnetically saturate the Faraday rotator and a solenoid coil for applying a variable magnetic field to the Faraday rotator in a direction of the optical axis. A fixed magnetic field is applied in the <211> direction, in which the Faraday rotator is likely to be magnetically saturated. The Faraday rotator can be saturated with a low magnetic field of about 100 Oe. The permanent magnets may employ ferrite permanent magnets, which have weak magnetic forces. A variable magnetic field may also be reduced. Therefore, an air-core coil can be used.