Disclosed are semiconductor laser devices which hardly have degradation
when used to generate high power of 200 mW or greater over a long period of time.
An exemplary semiconductor laser device comprising a semiconductor substrate, and
a layer structure formed on the semiconductor substrate and having an active layer
with a quantum well layer formed of a ternary system mixed crystal of a III-V compound
semiconductor. The material of the quantum well layer is formed in an equilibrium
phase which is thermodynamically stable at both the growth temperature and the
operating temperature. The material preferably has a substantially homogeneous
disordered microstructure. In a preferred embodiment, the material comprises GaAsSb.
The quantum well layer exhibits improved thermodynamic stability, and the device
can emit light in the 980 nm band at high power levels for longer periods of time
without failure in comparison to conventional InGaAs 980 nm pumping lasers.
