| 摘要 |
PURPOSE:To obtain a waveguide type branching-coupling element which can couple wave-guiding light waves at arbitrary intensity by inserting a pair of couplers to branch and couple bidirectional light waves and a light amplifier between the main waveguide made up on a semiconductor substrate and a sub-waveguide connected thereto with a T-type or Y-type crossing portion. CONSTITUTION:The light wave 17 incident from a sub-waveguide 13 is bidirectionally branched to a main waveguide passage 14 at intensity of -6dB by a coupler 10b. A light wave 18a is radiated at intensity as it is from the main waveguide 14, but as a light wave 18b is subjected to a loss by -6dB when it transmits a coupler 10a, the amplification factor of a light amplifier 11 is set such that the loss can be compensated to make it possible to bidirectionally guide a light wave at the same intensity. When a light wave 16a transmits the coupler 10b, it suffers a loss of -6dB in the same way as above, so that the light wave bidirectionally guided through the main waveguide passage 14 can be guided to a sub-waveguide 12 at the same intensity by setting the same amplification factor as above at the light amplifier 11. |
