| 摘要 |
PURPOSE:To improve coupling efficiency and to increase a quenching ratio and a demultiplexing ratio by arranging prisms on a PLZT thin-film optical wave guide, and transmitting light waves reflected by total reflecting surfaces in the prisms to said optical wave guide. CONSTITUTION:The prism 21 and 21' are arranged on a PLZT thin film 11 and optical wave guides 12 and 13, and light reflected by the total reflecting surfaces 33 in the prisms is transmitted to the optical wave guides 12 and 13. In this case, distributed index lenses 32 and 32' are provided between optical fibers 16 and 17, and the prisms 21 and 21' so as to transmit the light wave 32 from optical fibers 16 and 17 to the optical wave guides 12 and 13; and the single-mode fiber 16 is used for the input of the light wave and the multimode fiber 17 is used for the output of the light wave. Those distributed index lenses converges the light wave transmitted by the optical fiber 16, so the light wave is coupled while converged to a spread nearly as large as the optical wave guide width, obtaining high coupling efficiency. Consequently, the efficiency of fiber input is improved and the multimode fiber converges and couples light waves in various modes. |
