Patent ID: 9366835
Filing Date: 2016-06-14
CPC Classification: G02B

Claim Text:
1. An integrated optical semiconductor device comprising: a substrate having a principal surface and a back surface opposite to the principal surface, the substrate including a first region and a second region arranged in a first axis direction; a plurality of light receiving devices disposed on the principal surface in the second region of the substrate, each light receiving device including a low cladding layer including are n-type semiconductor layer and a light receiving layer disposed on the low cladding layer; a multimode interference coupler disposed on the principal surface in the first region of the substrate, the multimode interference coupler including a first cladding layer and a core layer disposed on the first cladding layer, the multimode interference coupler including output optical waveguides that are optically coupled to corresponding light receiving devices; a first conductive layer disposed on the back surface in the first region of the substrate; a second conductive layer disposed on the back surface in the second region of the substrate, the second conductive layer being electrically insulated from the first conductive layer by a gap between the first and second conductive layers; and a plurality of capacitors disposed on the principal surface in the second region of the substrate, each of the capacitors including a first electrode electrically connected to one of the light receiving devices and a second electrode electrically connected to the second conductive layer, wherein the substrate is made of a semi-insulating semiconductor material, and the first cladding layer of the multimode interference coupler includes the n-type semiconductor layer of the light receiving devices.