High-power, diffraction-limited-beam operation from interferometric, phase-locked arrays of AlGaAs/GaAs diode lasers

Abstract
10/11‐element interferometric phase‐locked arrays with optimized facet coatings operate in array mode L=8, diffraction limited to 200 mW at 2.7 times threshold, and in beam patterns 1.4 times the diffraction limit to 290 mW at 4.3 times threshold. Unlike Y‐junction‐coupled arrays, the beam pattern quality is not sensitive to the facet(s) reflectivity value(s). Transformation to a single‐lobe pattern requires a simple phase‐corrector coating or plate. The device beam pattern as a function of the array geometry is discussed.