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.
@article{arxiv.2410.22441,
title = {Microsecond electro-optic switching in the nematic phase of a ferroelectric nematic liquid crystal},
author = {Kamal Thapa and Sathyanarayana Paladugu and Oleg D. Lavrentovich},
journal= {arXiv preprint arXiv:2410.22441},
year = {2024}
}