| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To drastically downsize a device as a whole by reducing not only the dimension in an optical axis direction, but also the dimension in a direction perpendicular to the optical axis. <P>SOLUTION: A reflective variable magneto-optical device is equipped with: a group of optical elements with at least a birefringent element 12 and a variable Faraday rotator 16; and a mirror 18. The device controls the quantity or path of light while light incident from the one end side proceeds through the group of the optical elements and reaches the mirror on the other end side and the reflected light returns through the group of the optical elements and is outputted from the one end side and thus the light is made to go and return through the group of the optical elements. A Faraday element 24 being a variable Faraday rotator is placed on the light path directly before the mirroring means. An electromagnet 28 comprising a rod shaped core 30 with a coil 32 wound thereon is aligned in the vicinity of, and placed opposite to, the mirroring means so as to make one end face thereof placed just behind the mirroring means. A variable magnetic field is applied by the electromagnet to the Faraday element beyond the mirroring means. The device is applicable not only to a variable optical attenuator to control the quantity of light, but also to an optical switch to control the path of light. <P>COPYRIGHT: (C)2004,JPO</p> |
