In this paper, the concept of holographic storage and reproduction of optical signals is generalized for the case of a spectrally highly selective recording medium, which in addition to fixing the spatial intensity distribution of the incident light is also able to memorize its intensity spectrum. We demonstrate persistent storage, recall and conjugation of picosecond light signals from various model objects by making use of coherent optical responses in photochemically active media. A simple linear theory of holographic storage and playback of both the spatial and the temporal behaviour of the signal is shown to well describe the experimental results obtained by utilizing octaethylporphin-doped polystyrene at 1.8 K as a spectrally selective recording material. The proposed method of time- and space-domain holographic recording provides the storage and reproduction of time-dependent optical signals with a duration of 10-8 to 10-13 sec. This presents unique possibilities for ultrahigh-speed data-storage and optical signal-processing.
"Picosecond Time- And Space-Domain Holography By Photochemical Hole Burning", Proc. SPIE 0673, Holography Applications, (15 January 1988); doi: 10.1117/12.939033; https://doi.org/10.1117/12.939033