Time Domain Optical Information Storage in Systems Capable of Photochemical Hole Burning
Original Publication Date: 1981-Nov-01
Included in the Prior Art Database: 2005-Feb-12
The stimulated echo effect is used in photochemically reactive systems to store and retrieve information. For writing, two short powerful pulses separated by the time T(w) are incident upon the medium. The first pulse excites the photochemically active species to a coherent superposition state, while the second pulse excites some of the centers to an excited state and stimulates others to return to the ground state. Some centers remaining in the excited state react chemically in an irreversible way and, thus, never return to the initial ground state. The information contained in T(w) is thus stored permanently. Multiple writing sequences with different values of T(w) record the information contained in those time intervals using the same inhomogeneously broadened ensemble of photochemically active absorption centers.