Patent Number: 6,480,636

Title: Optical isolator comprising a faraday rotator

Abstract: An optical isolator comprises an optical element assembly (10) including a Faraday rotator (1) and a pair of polarizing elements (2) one of which is arranged on a light-input side of the Faraday rotator (1) to serve as a polarizer and other of which is arranged on a light-output side to serve as an analyzer. The optical element assembly (10) is received at the center of an inner bore or a cavity of a cylindrical iron-chromium-cobalt (Fe--Cr--Co) magnet (5). The Faraday rotator (1) comprises a magnetic garnet thick film which is a Bi garnet thick film remarkably low in saturation magnetization as compared with a rare-earth garnet. The Fe--Cr--Co magnet (5) serves as a field-application magnet for generating a magnetic field applied to magnetize the Bi garnet thick film and also as an isolator casing because it is excellent in magnetic and mechanical characteristics.

Inventors: Satoh; Tadakuni (Sendai, JP), Kimura; Masayuki (Shiroishi, JP), Nakajima; Takahiro (Sendai, JP)

Assignee: Tokin Corporation

International Classification: G02F 1/01 (20060101); G02F 1/09 (20060101); G02B 006/00 ()

Expiration Date: 11/12/2019