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Holographic photothermoplastic disks with two-dimensional Fourier hologram registration obtained by infrared laser heating of the recording layer is described. These disks have high information recording density (~10(5) bits/mm(2)), high quality of the registered Fourier holograms (eta = 5-7%, contrast ratio 70:1), the possibility of information rerecording, and invariance to shift in thin phase holograms. A holographic-disk-based scheme of an optical neural network with outer-product implementation is suggested. The main advantages of this approach are discussed, and the results of such a neural network modeling are described.

A conjugate image plane correlator with holographic disk memory is proposed. Optical correlation between conjugate images reconstructed from a holographic disk and an input image on liquid-crystal television is executed with the rotation of the disk. Regardless of Fourier hologram recording with the pseudorandom diffuser, it is found possible to take out the diffuser from the original hologram recording scheme using an image reconstruction process and to get correlation signals between input and reconstructed conjugate images in the output plane of a tw0-1ens imaging system. Generation of conjugate replicas with high contrast causes exact matching with an input image which results in high recognition performance for autocorrelation signals. The transfer function of an optical system can be controlled by adjustment of either hologram size or hologram area illuminated with a laser beam. Hence, the output intensity distribution can be adjusted by selecting a proper pupil function and the size of an output pupil defined by the input pupil size and the optical system magnification factor. The real-time character recognition by optical parallel high-speed processing for twodimensional images with position normalization is demonstrated.

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