Above‐threshold analysis of antiresonant reflecting optical waveguide (ARROW) diode lasers has been performed. One key finding is that preferential pumping of the (central) low‐index core region dramatically enhances the device single‐mode power capability, as a result of defocusing and subsequent radiation‐loss increase for the first‐order spatial mode. Stable, single‐mode operation to drive levels ≳10× threshold is predicted for 6‐&mgr;m wide core devices, in excellent agreement with experiment. Similar performance is found to hold true for ARROW devices with cores as wide as 10 &mgr;m, although due to gain spatial hole burning, the far‐field beam pattern experiences mild broadening. Study of triple‐core ARROW structures of 20‐&mgr;m‐wide aperture shows stable fundamental‐mode operation to ≳10× threshold, thus raising the prospect for stable, single‐mode reliable operation to power levels as high as 1 W cw. ©1995 American Institute of Physics.