| 摘要 |
PURPOSE:To provide the optical switch which has the excellent connectability to optical fibers, is low in loss, has the excellent temp. stability of operation and high speed characteristic and has no dependency on polarization by using a material to effect a photochromic reaction as an ambient medium. CONSTITUTION:An optical fiber coupler is used as an optical directional coupler and a photochromic compd. 4 is used as the ambient medium of its optical coupling part. Signal light is introduced into one optical fiber 1 of the optical fiber coupler. A photoirradiation device 5 is connected to the other optical fiber 2. The irradiation light which induces a light induced change in refractive index in the photochromic compd. 4 is introduced into the optical fiber 2. The irradiation light from the optical fiber 2 leaks from a tapered part 3 of the optical fiber coupler and the refractive index of the ambient medium is changed by this evanescent light. Then, the optical paths are switched with the low loss at a high speed without dependence on polarization by irradiating this switch at a prescribed period with the light of either wavelength of the control light of two varying wavelengths. |
