An experimental, high density optical memory using MA color centers in KCI has been built to study the application of color centers as read, write, and erase computer bulk memories. MA centers are employed as a binary indicator by making use of their ability to reorient in the KCI lattice when excited with either  or  polarized 531-nm light. Information is read out with circularly polarized 531-nm light. Results indicate that writing times of less than 5 µsec and packing densities exceeding 106 bits/cm2 will be possible in a fully developed system.
J. Burt, H. Knoebel, V. Krone, and B. Kirkwood, "Experimental High Density Optical Memory Using the Dichroic Absorption of the MA Color Center," Appl. Opt. 12, 1213-1219 (1973)