High power cw operation of phased array diode lasers with diffraction limited output beam

Phased array diode lasers have been operated emitting predominantly in a single diffraction limited beam with full width at half-maximum of 0.8° in pulsed operation and 0.7° in cw operation and output power of 420 and 350 mW, respectively. The current in these lasers is confined to periodic stripes that are offset by a half period at two positions along the laser. In addition, the stripe width varies monotonically across the device while holding the period constant. The single lobed, far-field pattern occurs at 4° off the facet normal and suggests operation in the lowest order supermode of the asymmetric array.