A method and apparatus for coherent beam combining in an array of laser beam collimators. The array of laser beam collimators includes an array of a plurality collimating lenses, each lens intercepting a respective one of a plurality of divergent laser beams. Each collimating lens is joined with adjacent collimating lenses such that an output aperture is formed with a common vertex of the adjacently joined collimating lenses. A concave mirror is positioned a distance from the common vertex for receiving a fraction of each of the collimated laser beams that passed through a portion of each of the collimating lenses that are adjacent to the common vertex, and then providing reflected fractional collimated laser beams. A sensor intercepts the reflected fractional collimated laser beams so as to provide a signal that is applied to synchronize the phase of each of the collimated laser beams.