| 摘要 |
PURPOSE:To eliminate the radiation of light at the bent part of an optical wave guide and to obtain the high ratio of quenching at a port where signal light is outputted by directly forming a metallic film at the upper part and near the optical wave guide where a signal is not propagated without making a buffer layer intervene. CONSTITUTION:The buffer layer 3 at the upper part and near the optical wave guide 2A from the part of a directional coupler 6 to the port 6 being a dummy port is eliminated and the metallic film 5 is directly formed at the upper part and near the wave guide 2A. Then, the power of the TM mode of the light propagated in the guide 2A at the part of the film 5 and the light radiated at the bent part of the guide 2A are absorbed by the film 5. Besides, the light leaked from the dummy port which is coupled to the port C is reduced. Thus, the high ratio of the quenching of the signal light and high crosstalk are obtained. |
