FLOWS IN COMPOSITE LIQUID CRYTAL MATERIALS: NEW APPROACH FOR THZ APPLICATIONS

THz waves are of a wide usage in different modern applications like biomedicine telecommunications and security. The further progress in an elaboration of corresponding technical devices can be achieved due to usage of the... [ view full abstract ]

THz waves are of a wide usage in different modern applications like biomedicine telecommunications and security. The further progress in an elaboration of corresponding technical devices can be achieved due to usage of the units, like shutters, phase retarders, beam splitters, with tunable parameters. Liquid crystals are considered now as suitable materials for elaboration of such devices. Nevertheless, some new problems like low operating speed in relatively thick (about 1 mm) and restrictions in usage of an electric control due to high losses in electrodes have to be solved in this case.
In this report we propose the new approach to an elaboration of liquid crystals (LC) tuned THz devices, based on usage of shear flows. Flows are considered as more universal tool of LC orientation, which can be effective for both thin and thick samples. We consider the possibility of flow induced changes of optical properties for two types of composite LC materials: layered structures and porous polymer films filled with liquid crystals. The results of combined action of flows and magnetic (electric) fields are analyzed from the point of view of perspectives for THz applications. The special attention is paid on the electro-osmotic flows of liquid crystals throw the porous membranes, which can be effectively used in THz units of different types.
This work was supported by the Ministry of Education and Science of the Russian Federation [project no. 14.583.21.0058]