Modulation of unpolarized light in planar aligned subwavelength-pitch deformed-helix ferroelectric liquid crystals

TL;DR

This study investigates how unpolarized light interacts with subwavelength-pitch deformed-helix ferroelectric liquid crystals, revealing that electric fields influence interference patterns through phase shifts without affecting fringe visibility.

Contribution

It provides experimental insights into the electro-optic behavior of DHFLC with unpolarized light, highlighting the role of Pancharatnam phase and phase retardation in interference patterns.

Findings

Interference pattern shift is governed by electrically dependent Pancharatnam phase.

Fringe visibility depends solely on phase retardation.

Unpolarized light produces interference insensitive to in-plane axis rotation.

Abstract

We study the electro-optic properties of subwavelength-pitch deformed-helix ferroelectric liquid crystals (DHFLC) illuminated with unpolarized light. In the experimental setup based on the Mach-Zehnder interferometer, it was observed that the reference and the sample beams being both unpolarized produce the interference pattern which is insensitive to rotation of in-plane optical axes of the DHFLC cell. We find that the field-induced shift of the interference fringes can be described in terms of the electrically dependent Pancharatnam relative phase determined by the averaged phase shift, whereas the visibility of the fringes is solely dictated by the phase retardation.