| 摘要 |
PROBLEM TO BE SOLVED: To provide semiconductor optical amplification device that realizes, with higher reliability at a lower cost, a method of detecting a strength of an output optical signal amplified by a semiconductor optical amplifier.SOLUTION: A semiconductor optical amplification device includes a semiconductor optical amplifier (SOA) 1 and an element for optical amplification factor detection (MPD)6. The SOA has an optical waveguide structure composed of a semiconductor pn junction and the MPD has a pn junction structure constructed at a position, which is not on the optical waveguide structure and at which it is possible to receive natural emission light from the SOA, and functioning as a photodiode. The pn junction structure is made of a semiconductor material having band-gap energy of a wavelength shorter than a wavelength band of light inputted from the outside. Intensity of the natural emission light is detected at all times on the basis of a detection signal from the pn junction structure. By controlling an injection current to the semiconductor optical amplifier using the detection signal, an optical amplification factor of the semiconductor optical amplification device is stabilized. |
