Refractive mesogens

In addition, mesogenic units are introduced in the polymer. The mesogenes are bonded in tbe same way as the azo dyes. They need not necessarily absorb the actinic light since they act as a passive molecular group. Their task is to intensify the light-inducible double refraction and stabilize it after the action of the light. ... 

The observed nonlinearity mechanism can be used hereafter to investigate the effect of impurities on the character of phase transitions in liquid crystals, inasmuch as the experiments afford a unique possibility of controlling the impurity density. To realize such investigations it is necessary to explain the form of the photoconformation transformations of mesogenic molecules. Once the intermolecular order parameter responsible for the change of the refractive index is determined, dynamic holography methods can be... 

Table 2. Molecular polarizabilities and refractive indices for a selection of mesogens.

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