| 摘要 |
<p>An optical attenuator having a wide dynamic range and a decreased dependence of the dynamic range on temperature. An optical attenuator includes a polarizer and an analyzer both arranged along the optical axis of a device for controlling the angle of Faraday rotation of the light transmitted by applying external magnetic fields in two or more directions to a garnet single crystal exhibiting a Faraday effect and varying the synthesized magnetic field. When the angle of rotation z of the plane of polarization rotated by an angle-of-Faraday-rotation varying device satisfies the equation Z = y ± 90 where y is the angle formed by the polarizer and the analyzer, the angle x formed by the plane of polarization of a light falling on the garnet single crystal or the plane of polarization of either of the lights whose planes of polarization are perpendicular to each other and the direction of the magnetic field perpendicular to the optical axis satisfies the inequalities: [(-z / 2) + 90 æ n]-12 ≤ x ≤ [(-z / 2) + 90 æ n]+ 12 (where n is any one of 0, 1, 2, and 3).</p> |
