High power semiconductor lasers with a quantum well structure.

The high power characteristics of broad stripe gain-guiding quantum well lasers have been investigated. High quality GaAs/AlGaAs quantum wells and quantum well lasers were grown on 0.5° misoriented (111) B GaAs substrates by molecular beam epitaxy. Reduction of the optical density in the laser cavity is effective for increasing the maximum light output of graded index separate confinement heterostructure (GRIN-SCH) type quantum well lasers. The reduction of series resistance by increasing the cavity length, which also reduces the current density, is also effective to increase the maximum light output. The maximum light output of 3.7W has been attained by using small optical confinement in the GRIN region and a long cavity of 750μm.