| 摘要 |
PURPOSE:To obtain the distribution feedback semiconductor laser of high productivity by removing an active layer and a light guiding layer in nearly center of a resonator, where the phase shift region composed of semiconductor of different refractive index from those of the active and light guiding layers is formed. CONSTITUTION:On an N type InP substrate 1, a P type InGaAsP light guiding layer 4 on which InGaAsP active layer 3 and a diffraction grating 200 are formed is formed and the layers 3 and 4 are removed in nearly center of the substrate 1, where a phase shift region 120 is formed. Over the whole surface of the region 120, a P type InP clad layer 5 is formed and a multilayer film wafer is formed. Further on that, a buried hetero structure is formed with two parallel grooves 50 and 51 present on both sides of a mesa stripe 52, after which a current blocking layer, a current enclosing layer, a buried layer are laminated in order. Then a current injection region 61 is formed on the above layers and a P-side electrode 70 is formed on the region 61 and furthermore, an N-side electrode 71 is formed. |
