| 摘要 |
PURPOSE: To provide a compact, high-speed opto-electronic IC type optical sensor in which an optical waveguide and a semiconductor photodetector are integrated monolithically. CONSTITUTION: This device comprises a first lower limit layer CiC on a semiconductor substrate S that has a refractive index of n1, a second waveguide layer CG whose refractive index n2 is larger than n1, a third upper limit layer whose refractive index n3 is larger than n2, and an absorptive layer Ab having a refractive index of n4, that absorb an evanescent wave from the CG layer. A partially reflecting layer CR having a refractive index of n5 other than the range limited by n1 and n2 is inserted between the lower limit layer CC and a second waveguide layer CG at the position opposite to the absorptive layer Ab. Thus, lights can be obsorbed completely, and response time can be also shortened. |
