1.6 W continuous-wave coherent power from large-index-step (Delta n approximate to 0.1) near-resonant, antiguided diode laser arrays

Near-diffraction-limited-beam continuous-wave (cw) operation has been achie ved to high powers from antiguided arrays with a large effective-index step between element and interelement regions. InGaAs/InGa(As)P/GaAs 40-element arrays (lambda = 0.985 mu m) emit in beams 2 x diffraction-limit (0.67 deg rees) at 1.6 W and 9 x threshold in cw operation. 1 W of the coherent cw po wer resides in the central lobe. The external differential quantum efficien cy and the threshold current are 40% and 0.4 A, respectively, for 1-mm-long devices of 191 mu m emitting aperture. The overall electrical to optical p ower conversion efficiency at 1.6 W output power is 23%. Modeling of the th ermal effects in cw operation on the array modes reveals that for high-inde x-step (similar to 0.1) near-resonant antiguided arrays thermal lensing har dly affects high-order modes, and as a consequence, 2 x diffraction-limited beams can be maintained to watt-range cw powers. (C) 2000 American Institu te of Physics. [S0003-6951(00)01210-9].