Microsecond electro-optic switching in the nematic phase of a ferroelectric nematic liquid crystal

TL;DR

This paper demonstrates a fast, microsecond electro-optic switching effect in ferroelectric nematic liquid crystals at relatively low electric fields, promising significant improvements for optical device applications.

Contribution

It introduces the MEMOP effect in ferroelectric nematic liquid crystals, enabling rapid and efficient birefringence modulation at lower fields than traditional methods.

Findings

Birefringence change of 0.04 at 20 V/um

Field-on and off times around 1 microsecond

Superior figure of merit compared to conventional liquid crystal switching modes

Abstract

Nematic liquid crystals exhibit nanosecond electro-optic response to an applied electric field which modifies the degree of orientational order without realigning the molecular orientation. However, this nanosecond electrically-modified order parameter (NEMOP) effect requires high driving fields, on the order of 100 V/um for a modest birefringence change of 0.01. In this work, we demonstrate that a nematic phase of the recently discovered ferroelectric nematic materials exhibits a robust and fast electro-optic response. Namely, a relatively weak field of 20 V/um changes the birefringence by 0.04 with field-on and-off times around 1 us. This microsecond electrically modified order parameter (MEMOP) effect shows a greatly improved figure of merit when compared to other electro-optical switching modes in liquid crystals, including the conventional Frederiks effect, and has a potential for applications in fast electro-optical devices such as phase modulators, optical shutters, displays, and beam steerers.