Optical information storage in condensed matter with stochastic excitation

We have performed a temporal structure analysis of subpicosecond signals retrieved in the time domain from a spectral modulation engraved in a photochemical hole-burning material. Two situations are examined experimentally. The first one corresponds to a spectrally programmed stimulated-photon-echo configuration, and the second one corresponds to simple optical data storage. The results are obtained in a sample of octaethylporphine molecules embedded in a polystyrene matrix. Broadband stochastic excitations are used both to write the modulation inside the inhomogeneous width of the ground level of the zero-phonon line and then to read the spectral information. An original field cross-correlation technique is used to sample the retrieved signals.