High-power (>10 W) continuous-wave operation from 100-μm-aperture 0.97-μm-emitting Al-free diode lasers

By incorporating a broad transverse waveguide (1.3 mu m) in 0.97-mu m-emitting InGaAs(P)/InGaP/ GaAs separate-confinement-heterostructure quantum-well diode-laser structures we obtain record-high continuous-wave (cw) output powers for any type of InGaAs-active diode lasers: 10.6-11.0 W from 100-mu Lm-wide-aperture devices at 10 degrees C heatsink temperature, mounted on either diamond or Cu heatsinks. Built-in discrimination against the second-order transverse made allows pure fundamental-transverse-mode operation (theta(perpendicular to) = 36 degrees) to at least 20-W-peak pulsed power, at 68xthreshold. The internal optical power density at catastrophic optical mirror damage (COMD) (P) over bar(COMD) is found to be 18-18.5 MW/cm(2) for these conventionally facet-passivated diodes. The lasers are 2-mm-long with 5%/95% reflectivity for front/back facet coating. A. low internal loss coefficient (alpha(i) = 1 cm(-1)) allows for high external differential quantum efficiency 774 (85%). The characteristic temperatures for the threshold current T-0 and the differential quantum efficiency T-i are 210 and 1800 K, respectively. Low differential series resistance R-s: 2 6 m Omega; leads to electrical-to-optical power conversion efficiencies in excess of 40% from 1 W up to 10.6 W cw output power, and as much as 50% higher than those of 0.97-mu m-emitting Al-containing devices. (C) 1998 American Institute of Physics.