Operating characteristics of single-quantum-well AlGaAs/GaAs high-power lasers

The operating characteristics of six types of graded-index separate confinement heterostructure single-quantum-well wide-stripe lasers grown by metalorganic chemical vapor deposition are reported. The lasers exhibited intrinsic mode losses as low as 3 cm^-1 and internal quantum efficiencies near unity. Measured differential gain coefficients range from 3.7 to 6.5 cm/A, and extrapolated transparency current densities range from 54 to 145 A/cm². These wide-stripe lasers are typically multilongitudinal mode and exhibit narrowing of the gain envelope and lateral far-field pattern as the cavity length increases. The high value of T₀(>200 K) at long cavity lengths in conjunction with the low current density permits junction-side-up operation to CW optical powers of 0.5-0.7 W/facet, at which level catastrophic facet damage occurs on the uncoated devices. A maximum power conversion efficiency of 57% was measured on the laser structure exhibiting the lowest threshold current