| 摘要 |
PURPOSE:To obtain an optical semiconductor device with which an optical communication light source, wherein direct polarization modulation system of small dynamic wavelength modulation is used, the drive method for optical communication light source, an optical communication method using thereof, and an optical communication system. CONSTITUTION:A semiconductor laser 1 is used as a communication light source. The semiconductor laser 1 is a structure in which two oscillation polarization modes, having different plane of polarization, are switched by modulating the current to be made to flow through a part of an optical waveguide. A means 2, with which two polarization modes having different plane of polarization of polarized output light of the semiconductor laser 1, a means with which one light of two polarization modes is coupled to an optical transmission path, and a photodiode 3, with which the remaining light is converted to an electric signal, are provided. The current to be made to flow to the semiconductor laser 1 based on an electric signal, is controlled in such a manner that the state of modulation of the light coupled to the optical transmission path 9 is stabilized. |
