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:
Jul. 09, 2002
Filed:
May. 19, 2000
Hirotaka Kawai, Minato-ku, JP;
Hiromitsu Umezawa, Minato-ku, JP;
FDK Corporation, Tokyo, JP;
Abstract
There is provided a Faraday rotation angle varying device in which external magnetic fields are applied from at least two directions to a garnet single crystal having a Faraday effect and a synthesized magnetic field is varied so that Faraday rotation angle of light which transmits through the garnet single crystal is controlled. The device has a base film of garnet single crystal having a rotation angle varied in accordance with variation of a synthesized magnetic field, and a compensating film of a garnet single crystal having a constant Faraday rotation angle. The base film has a wavelength coefficient sign and the compensating film has a wavelength coefficient sign which is different from that of the base film, so that a wavelength variation component of the Faraday rotation angle of the base film is reduced by the compensating film. For example, a fixed magnetic field parallel to a light direction is applied by permanent magnets and a variable magnetic field is applied by an electromagnet.