A model for the Pockels effect in distorted liquid crystal blue phases

TL;DR

This paper presents a continuum-based model incorporating sub-unit-cell structure to explain and quantify the Pockels effect in distorted liquid crystal blue phases, predicting significantly larger electro-optic coefficients than traditional materials.

Contribution

It introduces a novel model that accounts for flexoelectricity and sub-unit-cell structure to explain the Pockels effect in distorted blue phases, aligning with experimental observations.

Findings

Model accurately predicts the Pockels effect within an order of magnitude.

Predicts Pockels coefficients could be 100 times larger than in lithium niobate.

Provides a quantitative framework for understanding electro-optic effects in blue phases.

Abstract

Recent experiments have found that a mechanically distorted blue phase can exhibit a primary linear electro-optic (Pockels) effect [F. Castles \textit{et al}. Nature Mater. \textbf{13}, 817 (2014)]. Here it is shown that flexoelectricity can account for the experimental results and a model, which is based on continuum theory but takes account of the sub-unit-cell structure, is proposed. The model provides a quantitative description of the effect accurate to the nearest order of magnitude and predicts that the Pockels coefficient(s) in an optimally-distorted blue phase may be two orders of magnitude larger than in lithium niobate.