RECEIVER FOR OPTICAL SPACE TRANSMISSION

摘要

PURPOSE:To provide the receiver for optical space transmission with high light receiving efficiency at low cost by resolving the problem of high cost in case of using many photodetectors and the problem of bad light receiving efficiency in the case of using a conical-shaped reflecting device. CONSTITUTION:The outside of the device is formed in a cylindrical shape by a material with reflactive index as high as possible which lets light with wavelength for transmission. A shape with its inside dug out in conical shape with the cylinder coaxial is formed. An optical element 1 forming a reflection coating 11 such as metal is arranged inside of the conical shape so that the axis becomes vertical against the non-directional flat surface. Further, a projected lens 2 for converging light is arranged in the summit of the cone to the coaxis with the optical element 1. A photodetector 3 is arranged on the back focusing surface of the projected lens or near it. The ray made incident from the vertical direction to the axis of the optical element 1 is refracted at the cylinder surface and the light is converged through the convex lens 2 and received by the photodetector 3. Thus, the light receiving efficiency is improved.