Photoinduced anisotropy, four-wave mixing, and phase conjugation in materials based on bacteriorhodopsin

In the field of real-time optical processing and computing based on the principles of nonlinear optics and dynamic holography a key role belongs to recording materials. There are certain properties of bacteriorhodopsin (BR) that make it attractive for these applications. Materials based on BR have a very wide range of photoreply time from 100 s down to 10 ps depending on the preparation procedure, and an axtremely high spatial resolution limited by the dimensions of the molecules. Moreover, they are sensitive to the state of polarization of the recording light, due to molecular dichroism. In this report we analyse the mian optical properties of BR films and aqueous suspensions, discuss the mechanisms of the photoinduced anisotropy in these materials and dèscribe the results of nonlinear optics and dynamic holography experiments: nonlinear filtration, control of polarization, polarization-preserving phase conjugation based on vectoral four-wave mixing.