| 摘要 |
PURPOSE:To abate noises by a method wherein the effective refractive index at the central part of a current injection region is made higher along one direction of the P-N junction face of an active layer and the high-resistance current injection region is formed in the vertical direction to the direction. CONSTITUTION:A groove part 2 is formed in a substrate 1, and a clad layer 3, an active layer 4, a clad layer 5 and a cap layer 6 are successively formed. According to such a way, a distribution of effective refraction index, which is higher at the groove part 2 of the substrate 1 and is lower on both sides thereof, is formed along the P-N junction face of the active layer 4. A current injection region 7 is formed in the vertical direction to the direction along the P-N junction face by diffusion of Zn and a high-resistance region 10 irradiated with proton is formed at the central part of the region 7. Light generated in the active layer 4 propagates in the parallel direction to the belt-shaped current injection region 7, but as the central part is high resistive and has not been injected current, the single longitudinal-mode oscillation is always obtained in low noises. |
