| 摘要 |
<p>A small-sized and inexpensive polarizer capable of fast switching operation, an optical switch easily capable of accommodating an array structure and a matrix format, and a variable optical attenuator. A polarizer (14) comprising laminate coils (10a, ..., 10c) having a through hole, and a Faraday element (11) disposed in the through hole or in the vicinity thereof, a magnetic field generated by the coils being applied to the Faraday element. The Faraday element is so disposed as to allow light to pass in a direction perpendicular to its principal plane to apply a magnetic field in that direction. Magnetic retaining members (12) each consisting of a high-permeability magnetic material are preferably disposed at least at part of the outer peripheries of the coils. A Faraday element using a magnetic garnet crystal with remanent magnetization will provide a polarizer having a self-retaining function, and such a polarizer can be used for an optical switch.</p> |
