The beam quality of a radial laser array, quantified in terms of the <i>M</i><sup>2</sup> propagation constant, is determined as a function of array element configuration. A lower bound on array <i>M</i><sup>2</sup> is estimated for both phase-locked and nonphase-locked conditions. It is shown that, to achieve near-unity <i>M</i><sup>2</sup> array, either aperture filling or spatial filtering is required in addition to phase locking. An aperture-filling method suitable for radial arrays of CO<sub>2</sub> slab lasers is presented.
© 1998 Optical Society of America
James D. Strohschein, Herb J. J. Seguin, and Clarence E. Capjack, "Beam Propagation Constants for a Radial Laser Array," Appl. Opt. 37, 1045-1048 (1998)