Experimental verification of optical image encryption based on interference

We present experimental results to verify the optical image encryption based on interference. The optical experiment is performed by using a reflective phase-only spatial light modulator (SLM) to generate the desired phase retardations. A hologram plate is employed to record the modulated wavefronts in a double-step-holographic-exposure process. The experiment results are in good agreement with the numerical simulations of the encryption algorithm, which demonstrates the feasibility of the optical image encryption in actual optical systems.