SEMICONDUCTOR OPTICAL PHASE MODULATOR

PROBLEM TO BE SOLVED: To provide an electrically and optically stable semiconductor optical phase modulator which is provided with a structure for extracting holes from a p-type semiconductor barrier layer, be it in an npin structure or in an nipn structure, without increasing a process load and without reducing design flexibility.SOLUTION: A semiconductor optical phase modulator is provided at least in one location in an optical waveguide 31 with a structure 51 for extracting holes from a p-type semiconductor barrier layer 14 of the optical waveguide 31. The structure 51 includes a wiring portion 52 which is provided in a direction crossing the optical waveguide 31 and comprises a semiconductor that includes the p-type semiconductor barrier layer 14, and a p-type semiconductor barrier layer connection portion 53 which is connected to an end of the wiring portion 42 and comprises a semiconductor that includes the p-type semiconductor barrier layer 14 which is exposed at least in part. An exposed section 14a of the p-type semiconductor barrier layer 14 is electrically connected with an electrode 16 located above a second n-type semiconductor cladding layer 15.