Reduction of speckle noise in laser energy distribution on the target by means of a modified Fourier hologram and incoherent averaging technique

Abstract

Presented in this paper is the technique of formation of required laser intensity distribution on the target with reduced speckle noise. The method is based on the use of a modified Fourier hologram adapted to controlled phase modulators. Reduction of the speckle noise in the laser energy profile is obtained using multiple incoherent superpositions of synthesized holographic images. Each hologram is synthesized with a different random diffuser. The advantages of this method: relative simplicity of hardware; robustness with regard to distortions of any kind in the input beam and/or optical path of the scheme; controlled reduction of the speckle noise in the final energy distribution.