2018 article

Wide Field-of-View Nanoscale Bragg Liquid Crystal Polarization Gratings

EMERGING LIQUID CRYSTAL TECHNOLOGIES XIII, Vol. 10555.

By: X. Xiang n, J. Kim n & M. Escuti n

co-author countries: United States of America 🇺🇸
author keywords: polarization grating; liquid crystals; Bragg diffraction; field of view
Source: Web Of Science
Added: December 31, 2018

Here, we demonstrate a liquid crystal (LC) polymer Bragg polarization grating (PG) with large angular band- width and high efficiency in transmission-mode for 532 nm wavelength and 400 nm period. The field-of-view (FOV ) is increased significantly while preserving high diffraction efficiency by realizing a monolithic grating comprising two different slants. Using rigorous coupled-wave analysis simulation, we identified a structure with 48° FOV and 70% average first-order efficiency. We then experimentally fabricated and characterized the grating with a photo-aligned LC polymer network, also known as reactive mesogens. We measured 40° FOV and nearly 80% average diffraction efficiency. With this broadened and fairly uniform angular response, this wide FOV Bragg PG is a compelling option for large deflection-angle applications, including near-eye display in augmented reality systems, waveguide based illumination, and beam steering.