| 摘要 |
PURPOSE:To monitor the emitting state of light emitting elements easily, by the construction that a transmission and reception module coupled with an optical communication path using optical fibers is picked up for a part of optical signals. CONSTITUTION:The transmission and reception module 11 inputs an optical signal 31 transmitted in an optical fiber 15 to a photodetector 33, where the signal is converted into an electric signal and applied to a reception system circuit 35. Further, an electric signal supplied from a transmission system circuit 41 is applied to an optical fiber 17 after being converted into an optical signal 45 at a light emitting element 43. In selecting the element 43 as an element having a wide directivity toward the major direction, light leaks to a direction shifted from the major direction. This leaking light is led to a direction A via a through-hole shaped optical path 61 provided with an outer case 55 and a support stand 53 of the module 11, and the leaked light is monitored at the window with a monitor, allowing to monitor the light emitting state of the element 43 directly. Further, a movable shutter 63 is provided at the upper part of the window of the path 61 and the monitor window of the path 61 is shut, allowing to eliminate the effect of external lights. |
