Bacteriorhodopsin oriented in polyvinyl alcohol films as an erasable optical storage medium
Zhongping Chen, Aaron Lewis, Hiroyuki Takei, and Isaiah Nebenzahl

Applied Optics, Vol. 30, Issue 35, pp. 5188-5196 (1991)
http://dx.doi.org/10.1364/AO.30.005188

Abstract
Films of oriented bacteriorhodopsin have been formed in polyvinyl alcohol with excellent optical quality. Images with high contrast have been impressed and erased on these films. Second-harmonic microscopy has been used to read the image on a bacteriorhodopsin-polyvinyl alcohol film without erasure. The potential of these films for molecular information storage and computation is discussed.