Combination of Low-Index Quantum Barrier and Super Large Optical Cavity Designs for Ultranarrow Vertical Far-Fields From High-Power Broad-Area Lasers

When active regions that use low refractive index quantum barriers (LIQB) are combined with super large optical cavity (SLOC) designs in GaAs-based diode lasers, high-power operation with extremely narrow vertical far-fields is observed. However, LIQB designs are found to have lower slope efficiency and increased operation voltage. Comparison of experiment and finite element device simulation shows that this is due to hole accumulation at the edge of the active region. Example devices using an 8.6-μm thick SLOC deliver 30 W at 1065 nm with vertical divergence of 15.6° (95% power).