| 摘要 |
PURPOSE:To eliminate the need for branched long light guides and optical fibers and to facilitate the miniaturization and assembly of a three-dimensional waveguide type optical function element by disposing a photodetector which detects the light radiated from the main plane of this element to the main plane of the element. CONSTITUTION:The photodetector 11 which detects the light radiated from the main plane 3a is disposed to the main plane 3a of the three-dimensional waveguide type optical function element 12 of the device which puts input light L0 via an optical fiber 1 into the optical function element 12 and takes out the output light L1 subjected to the prescribed processing. The light of the part where the light taken into the photodetector 1 leaks is, therefore, subjected to the same processing as the processing of the output light L1 and the state of the output light L1 is monitored by monitoring the output signal of the photodetector 11. The need for the long light guide 13 for guiding the light to the optical fiber for monitoring is eliminated in this way and the optical function element 12 is miniaturized; in addition, the assembly is facilitated. |
