We present high peak-pulsed coherent power results from large-aperture, 1.55 &mgr;m antiguided laser arrays. The InP-based devices have a compressively strained InGaAsP double-quantum-well active region and are fabricated by two-step self-aligned metalorganic chemical vapor deposition. We have obtained 2.5 W front-facet peak power in a 2.6° wide beam [6×diffractionlimit (D.L.)], with 1.2 W in the central lobe, from 40-element, 250 &mgr;m aperture devices. The width of the central lobe remains constant from 4 to15×threshold.Devices with improved temperature characteristics and of geometry closer to the resonance condition provide 1 W peak power in a beam 1.2° wide(2.7×D.L.),with 61&percent; of the energy in the central lobe; and 1.75 W peak power in a 1.5° wide beam(3.5×D.L.)at heatsink temperatures between 15 and 45 °C. ©1998 American Institute of Physics.