Polarization holography with photoinduced anisotropy in bacteriorhodopsin

Polarization holographic gratings transform the polarization state of an incident wavefront. We have studied the diffraction properties of polarization gratings, formed with two orthogonal linearly or circularly polarized waves. For a polarization modulation recorded in the organic material bacteriorhodopsin, the diffraction efficiency and the diffracted wave polarization strongly depend on the polarization state of the read- out wave. We have given a simple theoretical treatment using the Fraun- hofer diffraction integral. The experimental results have been interpreted in terms of this simplified model.