| 摘要 |
PURPOSE:To obtain an optical switch which is inexpensive and decreases insertion loss by providing a dielectric plate of which one surface is divided to a transmitting surface, semi-reflecting surface and full reflecting surface. CONSTITUTION:A semi-reflecting film 7' and a total reflecting film 8' are provided on one surface of a dielectric plate 6 of an optical part 5, by which a transmitting surface 9, a semi-reflecting surface 7 and a full reflecting surface 8 are formed thereon. When the parallel light 10 from a port P1 which converts exit light to parallel light is applied to the surface 9, the signal from the port P1 is fed to a port P2. When said light is applied to the semi-reflecting surface 7, the signal from the port P1 is fed to the port P2 and a port P3 and when said light is applied to the surface 8, the signal from the port P1 is fed to the port P3. The need for using a directional coupler in feeding the input signal to both or either one of the two output ports or feeding both or either one of the two input signals to the output ports is thus eliminated. The inexpensive optical switch which decreases insertion loss is obtd. |
