Patent ID: 7875905

Claim:
A semiconductor optical receiver device comprising: a semiconductor substrate; a mesa formed on the semiconductor substrate, including a plurality of semiconductor crystal layers, the plurality of semiconductor crystal layers including a pn junction having a first conductive layer and a second conductive layer; and a first electrode disposed with regard to the mesa and a second electrode disposed with regard to the semiconductor substrate, the first and second electrodes configured to apply an electric field to the pn junction, wherein: a contact portion of the first electrode disposed with regard to the mesa has an annular shape, an inner diameter of the first electrode disposed with regard to the mesa is larger than or equal to a diameter of the mesa, and the first electrode disposed with regard to the mesa has an annular shape, and in an inner side of the first electrode disposed with regard to the mesa, an anti-reflective portion is provided to transmit light entered from a surface of the device.