| 摘要 |
PURPOSE:To execute a high speed control and to reduce the control power by setting the length of a coupling area of an input side waveguide of light in accordance with complete coupling length. CONSTITUTION:In a fundamental optical switch element, a switching part 20 for switching transmission/reflection of light is provided on a part of a coupling area of a directional coupler constituted of two pieces of waveguides 11, 12 being adjacent in parallel. Also, the length of the switching part 20 is set so as to become shorter enough than the length of a coupling area 14, and also, the length of the coupling area 14 of the input side waveguide 11 of light is set to (n + 1/2) folds of the complete coupling length. In this regard, (n) = 0, 1, 2, 3.... Accordingly, a signal light which is subjected to a switching action is subjected to the same switching action in the 1 X 2 or 2 X 2 fundamental optical switch element of a final stage, as well, and outputted from an arbitrary output terminal. In such a manner, the operation can be executed at the high speed, and also, by low power. |
