1.6-W cw coherent power from large-index-step (Δ n=0.1) antiguided laser arrays

Near-resonant antiguided arrays with large effective-index step between element and interelement regions have been developed. 2.2 X diffraction-limited beamwidth (0.67 degrees) at 1.6 W and 9 X threshold in CW operation has been achieved. 1 W power resides in the central lobe. The external differential quantum efficiency and threshold current are 40% and 0.4 A, respectively, for 1 mm-long devices of 191 micrometer emitting aperture. The power conversion efficiency at 1.6 W is 23%. The thermal lensing effect in high-index-step near-resonant antiguided array hardly affects high-order modes and therefore, about 2 X diffraction-limited beam can be maintained to high powers.