| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable to easily form a tunable laser and to acquire a comparatively wide wavelength variable range with simple control. <P>SOLUTION: The tunable laser is provided with: an optical waveguide 1 having a gain waveguide section 1A generating a gain, and a wavelength control waveguide section 1B controlling an oscillation wavelength by current implantation or voltage apply, alternately in an optical axis; and a diffraction grating 2 provided along the optical waveguide over the entire length of the optical waveguide. The diffraction grating has: a diffraction grating 2A for gain to be provided on a position corresponding to the gain waveguide section; and a diffraction grating 2B for wavelength control to be provided on a position corresponding to the wavelength control waveguide. A wavelength control region 11B is configured so as to include the wavelength control waveguide section and the diffraction grating for wavelength control, and a gain region 11A is configured so as to include the gain waveguide section and the diffraction grating for gain. The tunable laser is configured so that a brag wavelength in the wavelength waveguide section is on a long wavlength side with respect to the brag wavelength in the gain region in the state where current implantation or voltage apply is not performed for the wavelength control waveguide section. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
