| 摘要 |
PURPOSE:To obtain a high efficiency distributed reflection type semiconductor laser by twice crystal growths by simultaneously executing a crystal growth for burying an active layer part and the formation of the two-dimensional photowaveguide of a distributed reflection region including a diffraction grating. CONSTITUTION:An N type buffer layer 2, an active layer 3 and a P type clad layer 4 are formed on an N type substrate 1. Then, the layers 4, 3 of the portion which becomes a distributed reflecting region 200 are removed, and a diffraction grating 20 is formed. Then, grooves 30, 31 are digged, and an active strip 32 and a reflecting stripe 33 are formed. This wafer is again introduced into a crystal growth furnace, and in the growths of a current block layer 6 and a current enclosure layer 7 for sequentially growing a current enclosure layer 7 of P type current block layer 6n, a P type buried layer 8 and a P type contacting layer 9, 2-phase melting method is employed. Then, both layers are formed at the top of the reflection stripe 33. When the sectional shape having a slightly thicker center is surrounded by InP having small refractive index, they operate as two-dimensional waveguide for propagating the light by enclosing it in the thicknesswise direction and in the direcion perpendicular to the thicknesswise direction. |
