To obtain a small-size and inexpensive optical rotator which enables fast switching operation, an optical switch which can easily respond to an array structure or a matrix form, and a variable optical attenuator which can easily respond to an array structure.
The optical rotator 14 is equipped with stacked coils 10a,...10c having a through hole and with a Faraday element 11 disposed in or near the through hole so that the magnetic field generated by the coils is applied on the Faraday element. The Faraday element is disposed in such a manner that light passes in the direction perpendicular to the principal plane of the element and that the magnetic field is applied in the above direction. A magnetism holding member 12 made of a magnetic material having high magnetic permeability is preferably disposed in at least a part of the periphery of the coils. When a magnetic garnet crystal having residual magnetization is used for the Faraday element, an optical rotator having a self-holding function is obtained, and the obtained rotator can be used for an optical switch or the like.
UMEZAWA HIROMITSU
RIKUKAWA HIROSHI
KITAOKA MIKIO
KAWAKAMI HIDEKI
ABE SHOHEI
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