Methods for three-dimensional optical data storage and retrieval

A three dimensional optical data storage and retrieval system that includes a three dimensional optical data storage medium and an apparatus for providing access to data stored on the medium. The data storage medium includes an optical data storage material which either a low molecular weight or polymeric glassy solid that are capable of undergoing multi-photon excitation that are energetically different in the write and read cycles. The optical data storage materials provide substantially higher storage capacities relative to conventional materials, and show high robustness in that written and stored data can undergo multiple read cycles without erasure or overwriting. An apparatus for data recording and accessing stored data on the medium includes a controllable variable energy photo-emitting excitation source and an emission photo-detector.