Beam Combining: High-power fiber-laser beams are combined incoherently

Combining laser beams can boost power at the target far above that produced by a single laser. Incoherent beam combining achieves propagation efficiencies of greater than 90%, while avoiding the complexities of coherent or spectral beam combining.

PHILLIP SPRANGLE, ANTONIO TING, JOSEPH PEÑANO, RICHARD FISCHER, AND BAHMAN HAFIZI of the Naval Research Laboratory (Bethesda, MD).
www.laserfocusworld.com/articles/331428