| 摘要 |
PURPOSE:To prevent the extension of oscillation spectral line width even on modulation at high speed while extremely reducing optical coupling loss by forming a laser region width an active layer and a diffraction grating, an optical waveguide layer and a modulation region and mounting a reflection inhibiting mechanism for beams to a projecting end surface. CONSTITUTION:A diffraction grating 16 is formed in a laser region 17 on an InP substrate 11, and an InGaAsP optical confinement layer 12, an InGaAsP active layer 13, an InP clad layer 14 and an InGaAsP cap layer 15 are shaped on the whole surface in succession. The laser region 17 functions as a distributed feedback type semiconductor laser, and oscillates at a single axial mode by injecting currents I1. The optical confinement layer 12 and the active layer 13 shaped in a modulation region 18 serve as an optical waveguide layer 113, and laser beams Pt are projected as an optical output P0 from an antireflection-coated end surface by an SiN film 112. Amplitude is modulated by currents I2 injected to the modulation region 18. |
