Superresolution in optical data storage

Abstract

By exploiting the threshold nature of the temperature of amorphization in a crystalline film of TeGeAs, digital information was recorded at a density higher than that obtainable with a linear storage medium. This information was read out optically with a scanning GaAs laser by choosing such an operating level for the laser that optical feedback from the crystalline state raised the laser above threshold, while feedback from the amorphous state did not. The use of these nonlinear techniques increases the recording and readout information density of an optical store beyond the limit imposed by optical diffraction. © 1973 American Institute of Physics.