Design of a passive waveguide for minimization of transverse beam dispersion in GaInP/AlGaInP visible quantum-well lasers

The design of a GaInP/AlGaInP visible separate confinement heterostructure quantum well (SCHQW) laser with passive waveguides is theoretically investigated using the transfer matrix method. By using this structure, we can significantly improve the transverse beam divergence with only a slight decrease of the optical confinement factor. With proper choice of parameters, a transverse beam divergence as narrow as 18° full width at half maximum (FWHM) can be achieved while the optical confinement factor only decreases by 0.3% compared to that of a laser without the passive waveguide structure.