Simulation analysis of random phase mask with spatial light modulator

To construct a real-time optical encryption system with spatial light modulator,the parameters of phase modulation were analyzed when utilizing spatial light modulator as phase modulators in the double random phase encoding system by means of simulation method.The influence of two important parameters,i.e.,the phase modulation range and the independent point numbers of phase modulation on the encryption quality was investigated extensively.A correlation coefficient was introduced to evaluate the difference between the original image and encrypted image.The simulation results indicate that a satisfying encrypted image can be obtained when the independent point numbers of phase modulation is approaching to 128×128 and the phase modulation range is set to 2π assuming that the correlation coefficient is 0.1.The results are significant for the design of real-time optical encryption system with spatial light modulator.