The fabrication and performance characteristics of InGaAsP (&lgr;∼1.3 &mgr;m) ridge waveguide laser arrays are described. The ridges have variable spacing but are chosen to be of equal widths so that the propagation constants, which determine the emission wavelengths, of the individual emitters are equal. The lasers have threshold currents in the range 300–350 mA at 30 °C and have been operated to pulsed output powers of 600 mW/facet. The far field along the junction plane is single lobed with a width characteristic of a phase locked, diffraction limited beam. Measurements of cw emission spectrum also show emission in a single fundamental supermode.