| 摘要 |
PURPOSE:To prevent the deterioration of the region located in the vicinity of a resonant surface due to concentration of energy by a method wherein the active layer located in the vicinity of the resonant surface is formed thicker than the other part, thereby enabling to reduce the energy density there. CONSTITUTION:A stripe-like convexity 4 is formed in the center part of a semiconductor substrate 1 and the first clad layer 5, having tapers 6 and 7 toward the direction of resonant surfaces 2 and 3, is provided above said convexity 4. Above the first clad layer 5, an active layer 8 having a band gap smaller than the first clad layer and a high refractive index of light, the second clad layer 9, a cap layer 10 and an electrode 11 are laminated successively. As a result, the thickness of the clad layer 5 is increased in the vicinity of the tapers 6 and 7, thereby enabling to concentrate the applied current at the convexity 4, and almost no current is flowing to the tapers 6 and 7. Accordingly, the energy concentration at the part in the vicinity of the resonant surfaces 2 and 3 can be suppressed, and the deterioration at this part can be prevented. Also, as the expansion angle of the beam is reduced when compared with that of the conventional product, a laser beam having a high coefficient of true roundness can be obtained. |
