| 摘要 |
PURPOSE:To form a film of inexpensive structure by scattering an unnecessary light beam in a light beam which is propagated in a plane optical circuit by a fine groove formed of fine thin holes formed in the surface of a dielectric. CONSTITUTION:The incident light 17 of a semiconductor laser 17 which is guided from an end surface of a plane optical waveguide 12 is diffracted with an acoustic surface wave 19, undeflected light 21 is cut off by a plane optical circuit spatial filter 23 and becomes scattered light 23, and only deflected light 20 is separated and incident on a photodetecting element 24. The filter 23 consists of a fine groove 61 formed of plural fine holes having overlap parts and cuts off the undeflected light 21', and the hole center pitch is varied to adjust the scattering effect by the projection and recess value H of the groove end surface. Thus, the device is constituted at low cost. |
