SEMICONDUCTOR LIGHT RECEPTION DETECTION CIRCUIT, OPTICAL CIRCUIT AND NONREFLECTIVE OPEN END PART

摘要

PROBLEM TO BE SOLVED: To suppress reflected return light to an optical circuit.SOLUTION: A semiconductor light reception detection circuit comprises an optical waveguide a3-in, a light reception detection part g1, an optical waveguide a3-out, and a mirror r1 having a reflecting surface inclined to an emission direction of signal light emitted from the optical waveguide a3-out. The light reception detection part g1 absorbs and converts at least part of signal light made incident from the optical waveguide a3-in into a current when applied with a reverse bias, and transmits the signal light made incident from the optical waveguide a3-in when not applied with the reverse bias. The optical waveguide a3-out has a tapered structure decreasing in waveguide width toward a propagation direction of the signal light passed through the light reception detection part g1. The mirror r1 is provided on an emission-directional extension of signal light emitted from the optical waveguide a3-out, and reflects the signal light in an upward or downward direction of a semiconductor substrate.SELECTED DRAWING: Figure 2