| 摘要 |
PURPOSE:To enable to perform high output with a thick active layer by asymmetrically forming the refractive indexes of two clad layers, between which an active layer is interposed, and increasing the leakage of a light from the active layer than symmetrical waveguides in the same active layer thickness. CONSTITUTION:An N type Ga1-xAlx-1As clad layer 12, a Ga1-yAlyAs active layer 13, a P type Ga1-x2Alx2As clad layer 14, and an N type GaAs cap layer 15 are sequentially grown on an N type GaAs layer substrate 11. The composition ratio of aluminum is set among the layers to x2>x1>y or x1>x2>y. When a forward voltage is applied, a current is concentrated to a diffused strip 16, and flowed, carried is enclosed in the layer 13 directly under it to form an inverted distribution. The light is enclosed in the layer 13, waveguided, amplified between mirrors formed by cleaving, and a laser oscillation is performed. At this time, since the refractive indexes of the layers 12, 13 are asymmetrical to the layer 13, the waveguided beam becomes the flared shape cut largely at the skirt at the clad layer having low refractive index to decrease the rate of waveguiding the layer 13, thereby increasing the output. |
