| 摘要 |
PURPOSE:To obtain a photoswitch of simple and rigid construction by branching only the specific one wavelength of the wavelength multiplex signal, and letting this light be shielded or transmitted. CONSTITUTION:An optical fiber 1 for transmission transmitting the wavelength multiple photo signal is interposed with a branching filter 2 and a wave combining device 3. The branching filter 2 takes out the light of the specific wavelength and transmits the light of other wavelengths, and the wave combining device 3 has the function of combining the light of the branched wavelength with the light of the other wavelengths. The light of the specific wavelength emitted from the 1st optical fiber 4 connected to the branching filter 2 is led into the 2nd optical fiber 5 connecting to the wave combining device 3. Hence, it is possible to know the condition of a light shielding plate 6 by detecting the presence or absence of the light of the specific wavelength in the light having been transmitted in the optical fiber 1. In this way, the photoswitch of the simple and rigid construction is obtained. |
