High-power semiconductor 0.89 – 1.06-μm lasers with a low emission divergence based on strained quantum-well InGaAs/(Al)GaAs structures

Heterostructure lasers with a separate electronic and optical confinement based on strained quantum-well structures with single and double InGaAs quantum wells and different waveguide parameters are studied. The heterostructure design and technological conditions of the quantum-well growth are optimised to increase the output power and reduce the laser emission divergence. Semiconductor lasers are fabricated with a cw output power as high as 4 W and the emission divergence of less than 30° in the plane perpendicular to the p – n junction plane. The pulsed output power of these lasers is limited by the catastrophycal damage of mirrors at a linear power density of 3000 W cm^-1.