Microsecond electro-optic switching of nematic liquid crystals with giant dielectric anisotropy

TL;DR

This paper demonstrates a rapid electro-optic switching method in nematic liquid crystals using a material with giant dielectric anisotropy, achieving microsecond response times at lower electric fields than traditional approaches.

Contribution

It introduces the MEMOP effect, enabling fast birefringence modulation with significantly reduced electric fields in nematic liquid crystals.

Findings

Significant birefringence change (~0.04) with a field of 3×10^7 V/m

Switching times of approximately 10 microseconds

Potential applications in fast electro-optic devices

Abstract

Nematic liquid crystals exhibit a fast optical response when the applied electric field modifies the degree of order but does not change the direction of molecular orientation. The effect requires a relatively high electric field, on the order of 10^8 V/m for a field induced birefringence change of 0.01. To address this detrimental issue, this work explores electrically induced modification of the order parameter in a material with a giant dielectric anisotropy of +200. A relatively weak field 3X10^7 V/m causes a significant change of birefringence, by about 0.04. Both switching on and off times are ~10 microseconds. The effect is called a microsecond electrically modified order parameter (MEMOP) and can be used in electro-optical devices, such as fast electro-optic shutters, phase modulators, and beam-steerers that require microsecond response times.