High-power seven-element grating surface emitting diode laser array with 0.012° far-field angle

Abstract
A coherent seven-element grating surface emitting diode laser array with a predominant single-lobe far-field pattern having an angular divergence of 0.012° has been demonstrated. The extent of the emitting aperture was 4 mm, and the beam divergence was within 10% of the diffraction limit. Under pulsed operation the array had a peak output power of over 400 mW and a differential quantum efficiency of 15%.