The physical meaning of a new electro–optical effect of conversion of polarization of optical signal during its propagation through a layer of thermodynamically irreversibly crystallizing liquid is given. Its effect on a linearly polarized signal is analogous to that of the Pockels electro-optical effect being at the same time more pronounced.
The transformation of the optical signal in an anisotropically crystallizing substance engendered by the irreversibility of the phase transition provides the basis for this effect, with the longitudinal dispersion of the natural-frequency of vibration of the molecular oscillator in a highly gradient crystallizing electric field playing the most important role.
New properties of optical radiation when it interacts with the substance in a thermodynamically nonequilibrium state are considered for water as an example.
The effect can be used as a new information characteristic of the strength of hazardous natural phenomena as well as of some transient phase transitions in production processes.