Abstract

Most holographic associative memories share a similar architecture, which is essentially a correlator with a retroreflecting thresholding device. The thresholding device performs two functions: it reduces cross correlation components, and it sharpens the correlation peak so that it is more like a δ function. In order to enhance the storage capabilities of the binary phase-only associative memory demonstrated in our previous work, these two operations must be improved. We have examined two techniques for this purpose; the first is de blocking, which improves the signal to noise ratio, and the second is cascading the BPOF with a Laplacian filter, which enhances the correlation peak and reduces the noise. Our results show that de blocking can enhance the storage capability by a factor of 4 and Laplacian filtering enhances the storage capability by a factor of 6.

© 1992 Optical Society of America