| 摘要 |
<p>PURPOSE:To obtain simultaneously the high gain and the high output of a semiconductor light amplifier by a method wherein light guide layers different from an active layer are respectively provided on the upper and lower parts of the active layer only on the light output side in the light amplifier. CONSTITUTION:A striped mask 21 having a void 22 of a width of 2mum is formed on an N-type InP substrate 11 with the surface, which is the face (100), in a direction which forms an angle of 5 degrees or larger with the orientation <011. A semiconductor stripe 26, which consists of a buffer layer 23, an active layer 13, a spacer layer 24, a light guide layer 15 and a clad layer 25, is formed in the void part 22 by a selective growth using an MOVPE method. The layers 25 and 15 are partially exched away excluding a region 14 on the output side of a semiconductor light amplifier. The mask 21 on the side of the stripe 26 is removed, the width of the void part 22 is widened to a width of 7mum and a clad layer 17 and a cap layer 18 are formed in such a way as to cover the stripe 26. The whole surface is covered with an SiO2 insulating film 19, the film 19 only on the horizontal surface of the layer 17 is removed and an electrode 1A is adhered on the whole surface of the substrate.</p> |
