| 摘要 |
PURPOSE:To decrease the insertion loss and the variance of isolation caused by a set optical path by constituting the branching or coupling means of an optical signal by using a total reflection groove, and also, arranging an optical waveguide so that the length of each optical path becomes equal. CONSTITUTION:Light beams which are made incident from one end of optical waveguides 1 - 4 are allowed to branch by total reflection grooves 15 - 18, and emitted through optical waveguides 12 - 14 having a gate function and other total reflection grooves 19, 20. In such a manner, by allowing the light beam to be branched or coupled by the total reflection action of the total reflection grooves 15 - 18, it is suffice that the depth of the groove is set to the depth extending over all the parts for guiding the light beam, and the manufacture is facilitated. Also, the total reflection grooves 15 - 18 utilize the total reflection action of the light beam, and by forming the optical waveguides 12, 13 to a shape obtained by folding an optical path by the optical wave guide 14 with the total reflection grooves 19, 20, each optical path length becomes equal. In such a manner, the insertion loss and the variance of isolation caused by a set path are decreased. |
