3D optical data storage

3D optical data storage is any form of optical data storage in which information can be recorded or read with three-dimensional resolution (as opposed to the two-dimensional resolution afforded, for example, by CD).

The origins of the field date back to the 1950s, when Yehuda Hirshberg developed the photochromic spiropyrans and suggested their use in data storage. In the 1970s, Valerii Barachevskii demonstrated that this photochromism could be produced by two-photon excitation, and at the end of the 1980s Peter M. Rentzepis showed that this could lead to three-dimensional data storage.

Second-harmonic generation has been demonstrated as a method to read data written into a poled polymer matrix.

Optical coherence tomography has also been demonstrated as a parallel reading method.