Patent ID: 8380032

Claim:
A semiconductor optical amplifier module comprising: a semiconductor device unit in which a semiconductor optical amplifier and a first semiconductor photo detector are integrated on a mutually same substrate, the first semiconductor photo detector being configured so as to monitor a part of an input light that is input to the semiconductor optical amplifier or a part of an output light that is output from the semiconductor optical amplifier; and a passive waveguide unit that is connected to the semiconductor device unit and in which a first passive waveguide and a second passive waveguide are provided on a mutually same substrate, the first passive waveguide being configured so as to cause the input light to be input to the semiconductor optical amplifier or to cause the output light to be output from the semiconductor optical amplifier, and the second passive waveguide branching from the first passive waveguide and being configured so as to cause a branched part of the input light guided by the first passive waveguide or a branched part of the output light guided by the first passive waveguide to be input to the first semiconductor photo detector.