Abstract

Recently there has been considerable interest in frequency domain optical memories based on the cryogenic phenomenon of photochemical hole burning.¹ This phenomenon occurs whenever persistent photochemical changes can be induced by exposure to narrowband optical radiation tuned to a frequency within the inhomogeneously broadened zero phonon line of a photoactive material contained In a host. The narrowband radiation selectively excites that fraction of molecules whose homogeneous linewidth overlaps the excitation frequency. The ensuing photochemical reaction results in a persistent narrow dip or hole in the line shape. Since typical ratios of inhomogeneous- to-homogeneous widths are of the order of 10³, 10³ resolvable holes can be burned into the inhomogeneous line at each spatial location in the sample. Thus the storage density in such a frequency domain optical memory might ultimately be 10³ higher than in a conventional optical memory.

© 1983 Optical Society of America