| 摘要 |
PURPOSE:To obtain a photocoupler which reduces the reflection and scattering of light, by arranging plural polarizing plates and attachable and detachable lambda/2 plates on the optical path of plural input/output terminals. CONSTITUTION:There are semiconductor laser light sources I1-I4; and the light outputs of the I1 and I3 have polarized components parallel to this paper surface, and those of the I2 and I4 have polarized component perpendicular to the paper surface. Polarizing filters (PF) 41-43 fixed among glass substrates 71- 73 reflect the vertical polarized components while allowing the parallel polarized components to pass. The lambda/2 plates 81 and 82 are freely attachable and detachable along thin slits made in the glass substrates 72 and 73. When the lambda/2 plates 81 and 82 are detached, the light from the light source I1 enters a light guide 3 through a parallel lens 51, the PFs 41 and 42, and a condenser lens 6. When the lambda/2 plate 81 is inserted, the light from the light source I2 is reflected by the PF41 to enter the light guide 3 through the lambda/2 plate 81 and PF42. Thus, the photocoupler which reduces the reflection and scattering of light is obtained. |
