Turbulence effect mitigation using adaptive optics post-processing of holographically recorded short-exposure images

We present a post-processing technique for mitigating the effect of turbulence on holographically recorded shortexposure images that consists of the two following sequential steps. First, the coherent field scattered from the viewed object propagates through a turbulence layer and is used to record a short-exposure Fourier hologram by interference with a know reference beam. Information about the instantaneous distorted optical field is hence stored permanently in the hologram. Secondly, the recorded hologram is read a posteriori using the reference beam with its wavefront modulated using adaptive optics. The resulting intensity image is used to compute a sharpness metric. Optimization of the metric is performed using a stochastic parallel gradient descent (SPGD) algorithm. Experimental and numerical results show an improvement of the image quality after convergence of the SPGD algorithm.