High-power single-mode AlGaAs lasers with bent-waveguide nonabsorbing etched mirrors

A nonabsorbing etched mirror structure for AlGaAs single-quantum-well graded-refractive-index separate-confinement heterostructure ridge lasers is analyzed with respect to mirror coupling coefficient, threshold current penalty, and far-field pattern. Measurements of the mirror temperature showed a reduction from 50 to 20 K at 30 mW optical power depending on the degree of overlap of the optical intensity with the absorbing bent-waveguide profile. Pulsed catastrophic optical damage power levels up to 400 mW and a thermally saturated cw power of 165 mW with single-mode operation up to 80 mW have been achieved. Lifetime measurements at 40 mW constant optical power indicated degradation rates ≤10-5/h comparable to AlGaAs lasers with cleaved and coated mirrors.