| 摘要 |
PROBLEM TO BE SOLVED: To reduce a threshold current density required for optical oscillation by forming an active layer with a specific property on a second semiconductor layer that is formed via a first semiconductor layer on a substrate main surface, forming a third semiconductor layer with a different property on it, and making the direction of the film thickness of the active layer different from the axis of one-axis anisotropy. SOLUTION: A second semiconductor layer 13 is formed on the main surface of a substrate 11 directly or via a first semiconductor layer 12, and an active layer 14 whose energy band gap is smaller than the second semiconductor layer 13 and is made of a semiconductor with one-axis anisotropy is formed on the second semiconductor layer 13. Further, a third semiconductor layer 15 with a larger energy band gap than that of the active layer 14 is formed on the active layer 14. Then, a pair of electrodes 17 and 18 for causing current to flow in the direction of a film thickness are provided on the second semiconductor layer 13, the active layer 14, and the third semiconductor layer 15, where at least the direction of the film thickness of the active layer 14 is different from the axis of the one-axis anisotropy. |
