| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a variable optical attenuator, which reduces the dependence over the entire part of the device upon wavelengths through optimization of a magnetic optical system by taking the dependence of a Faraday rotation angle upon wavelengths into consideration. SOLUTION: The variable optical attenuator has a Faraday rotor 1 which imparts variable Faraday rotation angles and a polarizer 2 and analyzer 3, arranged in front of and behind the Faraday rotor 1. The angle formed by the optical axis of the analyzer 3 with respect to the optical axis of the polarizer 2 is set, in such a manner that the Faraday rotation angle, when the dependence of an optical attenuation quantity on the wavelengths is maximized attains approximate 0, by which the dependence of the optical attenuation quantity on the wavelengths at the Faraday rotation angle is lessened.</p> |
