Electro-optical performance of polymer-stabilized sphere phase liquid crystal displays

Optical Filters Based on Cholesteric, Blue and Sphere Mesophases

An optical filter is one of the indispensable devices in massive and high-speed communication, optical signal processing, and display. Twist-structure liquid crystals, cholesteric liquid crystals, blue-phase liquid crystals, and sphere-phase liquid crystals show potential application in optical filters originating from the periodic nanostructures. Wavelength and bandwidth tuning can be controlled via temperature, electric fields, light, angle, spatial control, and templating technology. In this review, we discuss the recent developments of twist-structure liquid crystal filters.

Template Effect of Multi-Phase Liquid Crystals

The template effects on stability of twist structure liquid crystals (LCs) were investigated. By refilling a cholesteric LC (CLC) of different pitch into a blue phase LC (BPLC) template or a sphere phase LC (SPLC) template, a multi-phase and multi-pitch twist structure LC, which includes the refilling CLC and intrinsic template BPLC or SPLC, can be fabricated. By refilling a CLC of different chiral pitch into a CLC template, a multi-pitch CLC that includes the refilling CLC and intrinsic CLC, can be fabricated. Twist structure LC devices with multi-phase and multi-pitch show great potential for applications in optical communication, displays, and LC lasing.

A Tunable NIR Filter with Sphere Phase Liquid Crystal

A near-infrared (NIR) filter with sphere phase liquid crystal (SPLC) is proposed, which shows a low operating electric field and large temperature-gradient modulations. The central wavelength of the Bragg reflection can be thermally tuned from 1580 nm to 1324 nm with a temperature-gradient of 42.7 nm/K. Meanwhile, the central wavelength can be electrically tuned over 76 nm within a low operating electric field of 0.3 V/μm. Thus, the SPLC filter may achieve a wavelength variation of 256 nm by thermal modulation and 76 nm by electrical modulation. The SPLC filter shows great potential applications in optical communication devices.

Fast Switchable Dual-Model Grating by Using Polymer-Stabilized Sphere Phase Liquid Crystal

We demonstrated a fast switchable dual-model grating based on a polymer-stabilized sphere phase liquid crystal. To form binary periodicity layers, the polymer-stabilized sphere phase liquid crystal precursor was sequence ultraviolet cured at an isotropic and sphere phase. This grating jointly modulated both the phase and the amplitude, had six times the diffraction efficiency of that fabricated with polymer-stabilized blue phase liquid crystal. Moreover, the dual-model tunable grating shown polarization-independent and submillisecond response time, which may hold a great potential application in diffractive optics.