Experiment on long-term readout of binarized image in photorefractive memory with double mutually pumped phase conjugators

We demonstrate long-term readout of a binarized image with a dynamic refreshment technique by mutually pumped phase conjugate mirrors (MPPCMs). Long-term continuous readout without any fixing technique can be achieved by the refreshment with image-bearing beam resonance between the phase conjugate mirrors. Our technique additionally offers image binarization by intensity thresholding of MPPCM without any external image processing systems. In this paper, we show grayscale-to-binary conversion as well as long-term readout can be realized by adjusting the appropriate incident beam intensities and the coupling strength of crystals. We perform recording and retrieving experiment with barium titanate crystals and demonstrate the binarized image can be reconstructed over 10 min in the double MPPCM configuration.