| 摘要 |
PROBLEM TO BE SOLVED: To reduce oscillation threshold current density and to improve emission efficiency, by reducing warpage of a cavity of a semiconductor laser and hence improving parallelism of its end faces. SOLUTION: In a semiconductor laser 100 in which layers 2 to 9 each made of a gallium nitride compound semiconductor laser are formed on a surface a of a sapphire substrate 1, the longitudinal direction of a cavity R is oriented in the direction (m axis) perpendicular to a c axis of the substrate 1. When the gallium nitride compound semiconductor is epitaxially grown on the surface a of the substrate 1, the semiconductor grows along its c axis. At this time, the substrate 1 warps, with its warpage being smallest in the m axis direction. Therefore, when the cavity R is formed on the surface a so that the optical axis is oriented in the m axis direction, the parallelism of both end faces S is increased. |
