Five optically coupled narrow stripe (3.5 &mgr;m) GaAs/GaAlAs semiconductor lasers on 8‐&mgr;m centers are operated as a spatially coherent phase‐locked laser array. Output beams with less than 2° divergence are observed up to 60 mW/facet output with a quantum efficiency of greater than 25%/facet. Significant nonlinearities do not appear until well over 100 mW/facet output.