| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor optical amplifier with a simple structure that can improve noise characteristics. <P>SOLUTION: A semiconductor optical amplifier comprises a structure having multiple semiconductor layers including an active layer laminated on a substrate, which amplifies and guides a signal light from an entrance to an exit of an optical waveguide path in the active layer, and also irradiates an external light against the active layer by means of external light irradiation so as to decrease the number of carriers in the active layer. By the means of external light irradiation, the external light can be irradiated in a direction orthogonal to a direction of guiding the signal light in the optical waveguide path, and also can be irradiated to the active layer, at high optical intensity at the entrance and at low optical intensity at the exit of the signal light in the optical waveguide path. <P>COPYRIGHT: (C)2012,JPO&INPIT |
