US Patent 7221690 Semiconductor laser and process for manufacturing the same

This specification relates to a semiconductor laser in which an n-type semiconductor layer (13), an active layer (101), and a p-type semiconductor layer (24) are stacked in this order on a substrate (11), the active layer (101) comprising a well layer composed of InGaN, the semiconductor laser comprising an intermediate layer (21) sandwiched between the active layer (101) and the p-type semiconductor layer (24), and the intermediate layer including no intentionally added impurities and being composed of a gallium nitride-based compound semiconductor. This semiconductor laser has an extended lifetime under high optical output power conditions.