| 摘要 |
<p>PURPOSE:To prevent the interference of beams from a light-emitting element with a photodetector as faR as possible in a light-receiving and light-emitting section at the like for optical bidirectional communication by forming a recessed section to a base and mounting the photodetector in the recessed section. CONSTITUTION:The upper surface of a metallic base 1 consisting of aluminum is etched to shape a recessed section 1a. The base 1 is insulated, and a photodetector 2 is mounted on the base of the recessed section 1a. A light-emitting element 3 is mounted where near by the recessed section 1a and at a position where the photodetector 2 is not subject to the interference of beams extremely. The size or the like of the recessed section 1a are set previously so that the angle theta of light reception of the photodetector 2 is reduced extremely at that time. It is preferable that the base 1 is connected to ground potential in order to prevent noises.</p> |
