| 摘要 |
PURPOSE:To make the whole of a device small-sized and low-cost by monitoring input light of an optical amplifier and reflected light of output light by one light receiving module to reduce the number of light receiving modules. CONSTITUTION:The optical signal made incident on an input terminal 5 is amplified through an optical branching device 6, an optical amplifier 9, an optical branching device 7, and the optical branching device 6 and is outputted from an output terminal 10. Meanwhile, the incident optical signal passes the optical branching device 6 and the optical branching device 7, and reflected light on the side of the output terminal 10 passes the optical branching device 6 and the optical branching device 7, and they have power monitored by a light receiving modules 8. The output light of the optical amplifier 9 is branched by the optical branching device 7 and its power is monitored by a light receiving module 11. Optical branching devices 6 and 7 allow 90% of incident light to pass through in the straight propagation direction and allow 10% of this light to pass through in the branching direction. |
