A method for coherent addition of lasers is presented that uses binary phase-only gratings. It is shown that a grating that splits a single beam into N equal orders with high efficiency can be used in reverse to convert N laser beams into a single beam with the same efficiency. Experiments to demonstrate the conversion of seven beams to one beam are performed with a resulting conversion efficiency of 75%. An experimental apparatus is described that adds the power from both two and three He–Ne lasers (wavelength, 3.39 μm) with efficiencies as high as 83%.
© 1986 Optical Society of America
Original Manuscript: December 12, 1985
Manuscript Accepted: February 20, 1986
Published: May 1, 1986
Wilfrid B. Veldkamp, James R. Leger, and Gary J. Swanson, "Coherent summation of laser beams using binary phase gratings," Opt. Lett. 11, 303-305 (1986)