Weigert effect

Kondo, T. (1932). Uber den Photoanisotropen Effect (Weigert-effect) an Farbstoffen. I//Z, Wissenschafiliche Photogr, Photophys, Und Photochem., bd.31, H. 6, ss. 153-267 (German). 

First, azobenzene moieties exhibit photoinduced alignment leaving their transition moments perpendicular to the polarization of the incident LPL following the rules of Weigert effect [2]. Secondly, the ordered azobenzene molecules exert a rotational effect through molecular cooperative motion on the host photoinert mesogens. The... 

The anisotropic distribution of emitters can be generated even in an isotropic medium by the action of polarized light if this medium exhibits photodiemical activity, i.e. if photochemical reactions can take place in it at a rate dependiiig on the angle between the orientation of a particle and the electrical vector of the incident light wave (Weigert effect). Photoselection takes place in the medium, i.e, the emitters of a certain orientation are selected by the light. 

Photoinduced conformational changes in azo-dye-doped liquid crystals have been used for real-time holography [65]. The orientation of azo dyes by an optical field, the Weigert effect [66], has been used to induce orientation of liquid crystals both in the bulk and in alignment layers [67, 68]. 

Using a different setup based on the Weigert effect, " all optieal image addition and subtraction operations have also been demonstrated with the use of MRNLC films.The response time for these photoinduced molecular leorientational effects within the NLC films are in millisecond regime at an optical power of 1 mW. 

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