| 摘要 |
PURPOSE:To reduce the fluctuation of an oscillated wavelength at the time of direct modulation by a method wherein, in a semiconductor laser which has a waveguide layer with a corrugation of a Bragg wavelength which is a 1st wayelength and an active layer, a laser type phase control region whose oscillated wavelength is different from the 1st wavelength is provided. CONSTITUTION:A modulation region 40 in which the oscillation of a 1st wavelength is induced and a laser type phase control region 41 in which the oscillation of a 2nd wavelength is induced are coupled along the direction of a light axis. A bias current is injected into the laser type phase control region 41 to induce an oscillating state. Further, by applying a suitable control current to the laser type phase control region 41, the carrier density in the active layer 3 of the laser type phase control region 41 is changed with a high speed. With this constitution, the equivalent refractive index of the laser type phase control region 41 is controlled and the fluctuation of the refractive index of an active layer 4 created when the intensity of the light oscillated in the modulation region 40 is modulated is compensated so that the fluctuation of the oscillated wavelength can be suppressed. |
