Time-resolved Diffusing Wave Spectroscopy to Enable Ultrafast Electro-optic Relaxation Dynamic in Liquid Crystals

Abstract

Enabling control over a spontaneous dynamic process is a very complicated task in practice because of its statistical nature, and electro-optic (E-O) relaxation dynamic in a nematic liquid crystal (NLC) system is not an exception. Controlling E-O relaxation time requires an appropriate microscopic visualization. For that, a time-resolved diffusing wave spectroscopy (TR-DWS) is developed first time, and further demonstrated with that the linear E-O relaxation time of a NLC can be improved typically, from 25msec to 350{\mu}sec at room temperature, by controlling the orientational ordering of NLC. Apart from improving the linear E-O dynamic, it is expected that the application range of the proposed TR-DWS is likely to be extended to applications such as optical imaging in turbid media, coherent controlling and optical manipulation in complex quantum systems including miniature lasers, amorphous photonic crystals, and more.