The phenomenon of vector polyphotochromism was found earlier in some high-efficient polarization-sensitive materials depending on the radiant exposure of the inducing linearly polarized actinic light. This effect was observed at high radiant exposures. In this paper the vector polyphotochromic effect is considered when azimuthally dependent exposure is used. The principal difference in these two approaches is that, in exposure-dependent technique, the transmission spectrum of the material depends on the magnitude of the inducing light exposure and this dependence is non-linear. Therefore, certain tunable spectral profiles of the material are very difficult to be fixed, in particular, in the blue spectral region. In the use of the azimuthally dependent technique, the changes in the transmission spectrum are occurred depending on the polarization azimuth of the inducing light. It is shown that the advantage of this approach is the possibility of inducing this effect at much lower exposures of the exciting radiation and obtaining approximately linear dependence of the spectral characteristics of the material on illumination conditions. It should be noted the material used exhibits photochromic behavior of an unusual nature, which is based not on a slight change in the spectral characteristics of the pigment under the light action, but there are changes in the so-called interference color of the medium as a result of selective quenching the corresponding regions of the transmission spectrum of the given material. The polarizationsensitive materials based on biopolymer matrix and organic azo dyes have been used. The obtained results can be used for creating spectral-selective polarization element with high-speed.
It is known that polarization holography uses photoanisotropic materials to record the state of light polarization. The polarization-holographic method of storage, transformation, transmission and processing of information is one of the most promising directions not only in optical but also in general among information technologies. The potential of increasing sensitivity of certain types of materials to light polarization is not yet fully mastered. In this paper, azodyecontaining photoanisotropic polymers are represented as a result of the study of polarization-sensitive materials, which are distinguished from their predecessors by outstanding photosensitivity. The report shows results of improving the foreground photoanisotropic characteristics, such as: increasing the degree of light-inducible birefringence and the rate of acceleration of this process. Which is the main measuring criterion of photosensitivity and effectiveness of the studied materials. The efficiency of azodye based polarization-sensitive materials is based on integration of their components by forces of electrostatic interactions or covalent bonds. In our previous works we have repeatedly shown clearly all the advantages of the results achieved by the molecular electrostatic integration of the material components. The presented paper shows different advantages of photoanisotropic materials consisting of alternative, covalent bonds, from which the increased velocity of photoanisotrophy and significantly improved magnitude of photosensitivity are worth noting on the first hand. Based on the experiences accumulated as a result of the conducted recent research and the developed recommendations, the new polarization-sensitive materials have deliberately been synthesized and studied.
A new method of pattern recognition is presented which is based on obtaining photoanisotropic copies on the dynamic polarization sensitive material. The amplitude image of the object is illuminated by a linearly polarized light with a wavelength actinic for this material. In result a photoanisotropic copy of this image is induced on the polarizationsensitive material. In recognition process, a photoanisotropic copy is illuminated by circularly polarized light of a nonactinic wavelength. The distribution of elliptical polarization occurs behind a photoanisotropic copy and reduces to a summary ellipse in the Fraunhofer diffraction region. The parameters of this ellipse are related to the characteristics of the original object and uniquely identify the initial object. The polarization-holographic diffraction element developed by us enables to determine summary ellipse parameters - to obtain all the Stokes parameters in real time and to compare obtained results with recognizable object etalon in database. The method invariance to position, scale and rotation of pattern are investigated. The resolution and sensitivity of this method were also determined. The dynamic polarizationsensitive materials are reversible, with practically unlimited number of recording-deleting cycles. To obtain a photoanisotropic copy of another object on the same material, the previous copy should be deleted with a pulse of circularly polarized actinic light, then a next copy can be recorded. A laboratory model of the recognition device, appropriate software and a theoretical model were created. Database have been obtained by using images of various objects.
This paper presents the experiments on photoanisotropic organic media films based on the composition of the azodye and polymer containing different polyelectrolytes. As a part of an experiment to strengthen the cohesion of the matrix macromolecules, we individually added to the test compositions polyelectrolytes with variations of quantity and with the different nature. The kinetic curves of the inducing photoanisotropy in the polarization-sensitive films are shown. The addition of the electrolyte to this type of materials contributes to an early manifestation of vector polyphotochromic effect at low exposures, which in turn is a sign of improved photoanisotropic properties as this effect appears exclusively in high-performance polarization-sensitive materials.