| 摘要 |
PURPOSE:To double the number of data stations which can be installed, by setting the transmittance of half mirror of an optical switch to an optimum value in accordance with individual branch positions. CONSTITUTION:In an optical data way system where data is transmitted and received between data stations connected to a branch optical fiber 3 through plural optical switches provided between loop-shaped main optical fibers 1 and 2, each of optical switches SW consists of rod lenses 15-17 and a half mirror 19a whose transmittance is (m-1)/m and reflection factor is 1/m. The light from the main optical fiber 1 goes to a parallel light by the lens 15, and this light is made incident on the branch optical fiber 3 through the lens 17 by a total reflecting mirror when the optical SW is driven. When the optical SW is not driven, (m- 1)/m of the incident light is transmitted through the half mirror 19a and is made incident on the main optical fiber 2 through the lens 16, and the rest 1/m is reflected and is made incident on the optical fiber 3 and is monitored by an optical receiver. The evaporation area of reflection factor ''1'' of the mirror is changed to set the transmittance to an optimum value. |
