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

**Authors:** Suman Kalyan Manna, Laurent Dupont, Guoqiang Li

arXiv: 1901.07127 · 2019-01-23

## TL;DR

This paper introduces a novel time-resolved diffusing wave spectroscopy technique to significantly accelerate electro-optic relaxation in liquid crystals, enabling better control and potential applications in complex optical systems.

## Contribution

First development of a time-resolved diffusing wave spectroscopy method to visualize and control electro-optic relaxation dynamics in liquid crystals.

## Key findings

- E-O relaxation time improved from 25ms to 350μs at room temperature
- TR-DWS enables microscopic visualization of dynamic processes in turbid media
- Potential applications include optical imaging and quantum system control

## 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.

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Source: https://tomesphere.com/paper/1901.07127