| 摘要 |
PURPOSE:To realize an optical semiconductor element having high output power by specifying the optical confinement coefficient per quantum of a quantum well active layer, the total optical confinement coefficient of the active layer and the value of the reflectivity of an edge, respectively. CONSTITUTION:When the reflectivity of an edge is close to zero and a laser oscillating mode is not present, the expression I, wherein the gain, which is generated during the propagation in a waveguide is Gs, holds true. In this expression, GAMMA is the optical confinement coefficient, g0 is the gain coefficient, etai is the inner quantum efficiency, J is the density of the injected current, (d) is the thickness of an active layer, alpha is the waveguide-loss coefficient and 1 is the length of the waveguide. At this time, the active layer has the multiple quantum well structure, the inner quantum coefficient etai is increased, the gain coefficient g0 is made large and the confinement per quantum well for the confinement coefficient is made to be 0.05 or less. The gain saturation is not generated in the transition between base levels in this range. As the entire active layer, the single peak condition of the distribution of the light is satisfied when the confinement coefficient is made to be 0.3 or more and 0.6 or less. Thus, the optical semiconductor element having the high output power can be realized. |
