Improvement of combining efficiency of coherent beam combination from phase-locked laser array by Dammann grating

An efficient technique of utilizing Dammann grating and phase plate to get high power and high brightness laser beam from phase-locked laser array is presented. The conjugate Dammann grating and the phase plate are placed in the back and front focal plane of a Fourier lens respectively. In order to improve the beam combining efficiency, Continuous grating of high diffraction efficiency is used to replace the Dammann grating. Analysis shows that the Continuous grating which has a higher diffraction of efficiency is also suitable for beam combining of the presented system.