| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide magneto-optical components, such as variable optical attenuators, optical modulators and optical switches, which are small in size, low in power consumption and high in speed. <P>SOLUTION: The magnetic field of the same direction as the progressing direction of a light beam is applied by a permanent magnet 30 perpendicularly to light incident and exit surfaces of a Faraday rotator 20 and a light transmission region, completely included in, for example, a magnetic domain A region, emits light without attenuation. When an electromagnet 32 is energized to allow the region of the magnetic domain A and the region of a magnetic domain B to occupy nearly half of the light transmission region, respectively, the Faraday rotation angleθf turns out to be 0°. The light transmission region is made to be completely included within the region of the magnetic domain B by further increasing the current flow in the electromagnet 32. The Faraday rotation angle when the light transmission region exists within the magnetic domain B goes to -θfs. As the Faraday rotation angle changes to -θfs from 0°, the quantity of the light absorbed by a second polarizer 12 increases, and excellent attenuation is realized. <P>COPYRIGHT: (C)2004,JPO</p> |
