Because of the expense of making these crystals they are usually quite small. The can be quite thick compared to other mediums and can store a large number of holograms. The exposure energy is quite high and they are erased by light so reading the stored hologram degrades the image. Some researchers have gotten around the erase problem of these crystals. For further information see the the references at the bottom of the page.
Fe-doped LiNbO3 crystals have been used to store holograms. These crystals are only Available in small sizes but they are available in large thicknesses compared to traditional materials. This thickness can be used to make holograms that can be made to read different holograms when the reference beam comes from different angles.
Reading the hologram at the same frequency as writing it will cause degredation of the image.
The exposure requirement is quite high at about ^4 J/m^2.
The interested researcher should refer to Petrov, M.P. (1979) Light diffraction from volume holograms in electro-optic bifringent materials. Optics and Laser Technology. 11, 149-151.
Exposure requirement - 3J/M^2. This material is used with an applied field perpendicular to the fringes. This applied field can be up to 900V/mm.
Information storage length for dark storage is reported to be only 30 hours.
Optical Holography, P. Hariharan, 1996, ISBN 0521439655