| 摘要 |
PURPOSE:To obtain a light source which has no spectral noise by disposing one or more sets of diffraction gratings of corrugated periodic structure which is disposed in a plane parallel to the active layer and has apodized amplitude distribution on the boundary between two arbitrary layers of an active layer, a waveguide layer, a clad layer, and the first grown layer of substrate side. CONSTITUTION:A diffraction grating which has a corrugated periodic structure represented by N(lambda0/2ne) where N is integer number, lambda0 is wavelength in vacuum of laser light, ne is effective refractive index is provided on the boundary between two arbitrary layers of an active layer, a waveguide layer, a clad layer, and the first grown layer of a substrate side. In other words, an N type InP layer 73, N type, P type and I type In0.7Ga0.3As0.6P0.4 clad layers 71, 72, an In0.6Ga0.4As0.86P0.14 active layer 70, a P type InP layer 74, a P type In0.6Ga0.4 As0.86P0.14 cap layer 741, an SiO2 layer 79, an ohmic contacting Cd diffused layer 78, and electrodes 77, 791 are formed on an N type InP substrate 76, and a diffraction grating 75 is formed on the boundary between the layers 71 and 73. |
