OPTICAL ISOLATOR

PROBLEM TO BE SOLVED: To provide an optical isolator allowed to be miniaturized without requiring complicated constitution, a specific material, etc. even in the case of connecting a plurality of Faraday rotators. SOLUTION: The optical isolator provided with Faraday rotators 1, 2, polarizing elements 11, 12, 13 arranged alternately with the Faraday rotators 1, 2 along a light transmitting direction and permanent magnets 21, 22, 23 magnetized vertically to the light transmitting direction and arranged so as to apply magnetic fields to respective Faraday rotators 1, 2 in parallel with the light transmitting direction. Where, two or more Faraday rotators are arranged, the number of polarizing elements and the number of permanent magnets are respectively larger than the number of Faraday rotators each by one and the magnetizing directions of the mutually adjacent permanent magnets are turned to mutually reverse directions. A magnet having cylindrical structure composed of a dividing member divided into a plurality of parts in the peripheral direction is used as each permanent magnet. COPYRIGHT: (C)2007,JPO&INPIT