Holographic recording with orthogonally polarized waves in centrosymmetric Na ₂ [Fe(CN) ₅ NO]·2H ₂ O

Recording of holographic gratings by excitation of long-living metastable electronic states in centrosymmetric sodium nitroprusside can be performed with mutually orthogonal polarized waves. Two different cases have to be distinguished: 1) In a b -cut the optimum diffraction efficiency of 15% is achieved if the mutually orthogonal polarized writing waves form an angle of 45 ° with respect to the a - and c -axis. This, together with the fact that the polarization state is not changed in the diffraction process, indicates that the gratings originate from the presence of light-induced linear dichroism. 2) For a c -cut the polarization of the diffracted wave turns out to be orthogonal to the one of the incident beam. The efficiency of this so-called anisotropic diffraction reaches a maximum of up to 90% for waves mutually orthogonal polarized along the a - and b -axis.