We demonstrate high-power InAsSb/InPAsSb laser bars(&lgr;≈3.2 &mgr;m)consisting of three 100-&mgr;m-wide laser stripes of 700 &mgr;m cavity length, with peak output power up to 3 W at 90 K, and far-fields for the direction perpendicular to the junction as narrow as 12° full width half maximum. Spectra and far-field patterns of the laser bars are shown to have excellent characteristics for a wide range of operating conditions, suggesting the possibility of even higher light power emission with good beam quality. Joule heating is shown to be the major factor limiting higher power operation. ©1997 American Institute of Physics.