Polarization-independent submillisecond phase modulation utilizing polymer/short-pitch cholesteric liquid crystal composite

Abstract

A broadband, polarization-independent phase modulation spanning the visible range is demonstrated using a polymer/cholesteric liquid crystal composite with optical pitch in the ultraviolet. Polarization insensitivity is achieved as a result of two effects: (1) optical anisotropy of the rod-like molecules is canceled out by the short helical pitch, and (2) stabilization of the Grandjean texture by the polymer network suppresses depolarization. Polarization-independent modulation of the refractive index by approximately 0.045, corresponding to a phase modulation of π at 500 nm, is achieved with submillisecond response times. Our material system opens new avenues for polarization-independent, tunable optical devices, such as narrow bandpass filters, gratings, and adaptive lenses.

Pseudopeptidic Polymer Microsphere-Filled Liquid Crystals as High-Performance Light-Scattering Switches

“…Among all, LC-based devices are more economical and efficient owing to their reliability, cost effectiveness, and low operating voltage requirement . The mechanical and thermal properties of LCs are further enhanced by combining them with polymer materials to form liquid crystal polymer composites (LCPCs) with improved switching properties. − These materials have dynamic electro-optic (E-O) properties and are, therefore, excellent candidates for the fabrication of optoelectronic devices. LCPCs have many benefits over conventional LC-based devices, such as nondegradability over time and no requirement of a polarizer in addition to their enhanced resistance to thermal and mechanical stress. − …”

Photo-Polymerization in Chiral Dopant Liquid Crystal Cells via Holographic Exposure to Fabricate Polarization-Independent Phase Modulator with Fast Optical Response

“…Even if this holds true, available PDLC phase modulation is not large enough for real applications. In contrast, anisotropic monomers are also available for fabricating polarization-independent phase modulators in homeotropic PNLC cells [22], polymer stabilized cholesteric LC cells [23], and polymer stabilized short-pitch planar cholesteric LC cells [24]. Polarization-independent LC phase modulators with anisotropic monomer dopant usually possess a larger phase modulation, but higher voltages are also needed during operation.…”