| 摘要 |
PURPOSE:To reduce the amount of spontaneous light emission by a method wherein the carrier density of a P type clad layer is set over the fixed value, in a double hetero junction type semiconductor laser equipped with the P type and an N type clad layers respectively by sandwiching an active layer. CONSTITUTION:The double hetero junction type semiconductor laser is equipped with the N type clad layer 2 and the P type clad layer 4 by sandwiching the active layer 3. The both clad layers 2 and 4 have energy band gaps wider than that of the active layer 3, and the light refractive index is set small. In such a semiconductor laser, the relation between the carrier density of the P type clad layer and the amount of spontaneous light emission is when the carrier density becomes 10<18>/cm<3> or more, the amount of spontaneous light emission decreases rapidly. Therefore, the amount of spontaneous light emission can be reduced by selectively the carrier concentration in such a manner. |
