TURBULENT PHASE SCREEN FOR THE STUDY OF IMAGING-SYSTEM PERFORMANCE

We introduce a nonlinear optical technique for the creation of small-s cale phase distortions in coherent optical systems. This technique use s the nonlinear response of a liquid-crystal light valve placed in a t wo-dimensional optical feedback system to produce a controllable spati ally and temporally varying chaotic intensity distribution. The intens ity pattern is converted into a spatially varying thin phase screen us ing a second liquid-crystal light valve. A chaotic phase distortion is then introduced into the output image of a coherent imaging system by propagation through the phase screen.