Self-conjugation heteroassociative memories using thin static nonlinearly recorded holograms

Abstract

The problem of all-optical holographic associative memory is elaborated with account of recording nonlinearity of thin static off-axis holograms. It is shown that the recording nonlinearity results in reconstruction of angularly separated diffraction orders, in one of which (minus 2nd) the complex congugate associative response is reconstructed as such a hologram is read out by incomplete version of the stored pattern. Being angularly separated from the readout beam, the phase conjugate response occurs be error-corrected. Moreover, recording nonlinearity provides unique feasibilities for associative coupling and reconstruction of heteroassociations beteween complex patternts accumulated at one carrier without interference. This feasibility obliged just to natural recording nonlinearity (`nonidealness') of registration medium leads to limit generalization of the concept of holographic associative memory.