| 摘要 |
PURPOSE:To control the wavelength by enabling the action by single axial modes by a method wherein a partial region of an active layer is provided with a diffraction grating of unevenness repetition whose period is given by a specific formula. CONSTITUTION:The active layer 3 is formed on a semiconductor substrate 1. A partial region of the active layer 3 or a partial region of a waveguide layer provided in adjacent to the active layer 3 is provided with the diffraction grating 100 of unevenness repetition whose period is given by a formula mlambda/2neff (neff; effective refractive index, m; positive integer, lambda; wavelength). Control electrodes 21 and 22 isolated for independent injection of charges are formed at the region with the grating 100 and at the egion without the grating 100. Then, the oscillation by single axial modes is enabled, and the oscillation threshold value or the oscillation wavelength can be controlled by controlling the current being passed to the control electrode 22. |
