Anthracene monomer-dimer photochemistry: High density 3D optical storage memory

Abstract
Ultrafast spectra and kinetics of all spectroscopic states and intermediate species in the photodimerization process of substituted anthracenes have been identified and measured by means of ultrafast spectroscopy. The two forms of this process, monomer and dimer, have been used to construct a 3D optical storage memory device capable of 1013 bits/cm3 density and very large bandwidth. Storage and accessing 3D information is based on non-linear absorption and the different structures of the monomer and dimer. This rather novel 3D memory device and its operation is described in detail.