BEAM-PROPAGATION CONSTANTS FOR A RADIAL LASER ARRAY

The beam quality of a radial laser array, quantified in terms of the M -2 propagation constant, is determined as a function of array element configuration. A lower bound on array M-2 is estimated for both phase- locked and nonphase-locked conditions. It is shown that, to achieve ne ar-unity M-2 array, either aperture filling or spatial filtering is re quired in addition to phase locking. An aperture-filling method suitab le for radial arrays of CO2 slab lasers is presented. (C) 1998 Optical Society of America.