Phased-array lasers which emit up to 575 mW in a 1.9 degree (FWHM) single far-field lobe corresponding to the lowest-order supermode are described. Single-lobe operation is achieved in lasers whose stripes are offset near the facet by half a period from the stripes in the central part of the cavity and are linearly chirped across the diode. This stripe geometry tends to lower the threshold of the single-lobe mode relative to that of the undesired double-lobe mode.