Patent ID: 7756169
Filing Date: 2010-07-13
Classification: H01S

Abstract:
1. A laser system comprising: a plurality of laser sources each producing a respective beamlet, one of said beamlets being definable as a reference beamlet, and all other beamlets being definable as non-reference beamlets; a beam combiner optically coupled to said laser sources for combining said beamlets into an output beam; each of said non-reference beamlets exhibiting a respective piston error characteristic, said piston error characteristics producing piston error artifacts in said output beam; a piston error controller employing a diffractive optical element to measure said piston error artifacts in said output beam and produce a correction signal related to said piston error characteristic of one of said beamlets; and a phase modulator interposed in said one of said beamlets for minimizing said piston error characteristic responsive to said correction signal.