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:
Sep. 11, 2001
Filed:
Feb. 26, 1999
Hirotaka Kawai, Shizuoka, JP;
Hiromitsu Umezawa, Aichi, JP;
Hidenori Nakada, Aichi, JP;
Nobuhiro Fukushima, Kanagawa, JP;
Other;
Abstract
Disclosed is a Faraday rotator capable of reducing the temperature dependence on a Faraday rotation angle, thereby enhancing the temperature characteristic, particularly, in a service environment in which the magnetization direction is variable, and an optical device using the Faraday rotator. The Faraday rotator includes a Faraday element which rotates the polarization plane of polarized light rays passing through the Faraday element when an external magnetic field is applied to the Faraday element. In this Faraday rotator, assuming that an angle between a magnetization direction of the Faraday element and a light ray direction is taken as &agr;, the amount of the temperature-dependent change in Faraday rotation angle is reduced by applying the external magnetic field in a direction in which a first amount of the change in Faraday rotation angle due to the temperature dependence on the angle &agr; and a second amount of the change in Faraday rotation angle due to the temperature dependence on the Faraday effect satisfy a relationship in which the sign of the first amount is plus or minus, the sign of the second amount is minus or plus, and the absolute value of one of the first and second amounts is less than twice the absolute value of the other amount, more preferably, substantially equal to the absolute value of the other amount.