Provided is an optical element comprising a biopolymer having an oriented
structure and a photoresponsive compound, such as a photochromic compound,
wherein at least a portion of the photoresponsive compound is incorporated
within the oriented structure of the biopolymer and wherein the oriented
structure is laminar with the planes of the laminar orientation being
aligned perpendicular to a surface of the optical element. Preferably, the
biopolymer is a liquid crystal polypeptide, such as ferroelectric liquid
crystal poly(.gamma.-methyl-L-glutamate), and the photochromic compound is
bacteriorhodopsin. Such optical elements may be utilized in a holographic
grating, in an optical correlator system such as for pattern recognition,
in a dynamic holographic recording system, and in an optical switch.