Frequency domain storage

The main features of a non-volatile, optical storage scheme which has the potential of storing on the order of thousands of data bits in the frequency domain (f) are described. The frequency dimension can be used independently of the two or three spatial dimensions thus creating a three dimensional x, y, f- or a four dimensional holographic storage scheme. This frequency multiplexing method can, in principle, lead to an increase in storage densities of two or three orders of magnitude. The described scheme is based on a method of laser photochemistry which is known as photochemical hole burning (PHB); its limitations lie in the nature of the low temperature photochemistry as will be discussed in some detail. © 1979 SPIE.