| 摘要 |
PURPOSE:To improve external quantum efficiency by constituting a semiconductor photo detecting device by using an optical amplifier part and a photo detecting part formed on the same substrate. CONSTITUTION:On a semiconductor substrate 1, the following are formed; a semiconductor layer 3 as a clad layer, a semiconductor layer 4 as an optical guide layer, a semiconductor layer 5 having a quantum well or multilayer quantum well structure, a semiconductor layer 7 as an optical guide layer, a semiconductor layer 8 as a clad layer, and a semiconductor layer 9 as a cap layer. In this case, a diffraction grating is formed as follows; a flat interface 10R is formed on one-half part between the layer 7 and the layer 8, and an interface 10A where protrusions and recesses are repeated is formed on the other one-half part. A laminated body having the layer 8 and the layer 9 is isolated into a laminated body 11A and a laminated body 12R by an insulating layer 12. An optical amplifier part A to which a light L is inputted from the outside is constituted in a region under the laminated body 11A. A photo detecting part R to which the light from the amplifier part A is inputted is constituted in the region under the laminated body 11R. |
