| 摘要 |
PURPOSE:To hold a narrow emitting spectral beam width and to make an oscillation wavelength variable by independently injecting a current to an active region having an active layer formed with a diffraction grating and a phase control region, and further feeding back a light externally to the phase control region. CONSTITUTION:An active region 1 and a phase control region 2 are provided. The active region 1 has an active layer 5 formed with a diffraction grating 4 for diffracting a light, and the phase control region 2 has an optical guide layer 3 formed continuously to the active layer 4 for varying a refractive index by an injected current. A current is injected to the active region 1 and the phase control region 2 by electrodes 6, 7 provided independently from each other. An emitting light from the emitting end face 9b of the optical guide layer 3 of the phase control region 2 of the laser light formed by oscillation is reflected on a reflecting mirror 10, and again introduced to the phase control region 2 as a feedback light. Thus, a narrow emitting light spectral beam width is held to vary the oscillation wavelength. |
