Fast refocusing lens based on ferroelectric liquid crystals

Anti-counterfeiting Behaviour of Organic-Inorganic Hybrid Silica Film with a Chiral Smectic C Structure

Artificial photonic materials based on chiral liquid-crystalline nanostructures have attracted increasing interests for their wide applications as sensors, anti-counterfeit measures, displays and colour filters. Although the structurally coloured films with chiral nematic structures or blue phases have been prepared, the ones fabricated by fixing chiral smectic C (SmC*) phases have been rarely reported. In this work, organic-inorganic hybrid silica (OIHS) films with a SmC* structure were reported for the first time. An organosilane (CSC) with an enantiotropic SmC* phase was synthesized. The OIHS films with a SmC* structure were fabricated by the polycondensation of CSC under an acidic condition. The colour patterns can be observed in the oblique view, but not be observed in the vertical view, which is mainly due to the light scattering of the nanoparticles on film surface and the selective Bragg reflection of film inside. Therefore, such properties make the OIHS films promising candidates for anti-counterfeiting applications.

Liquid crystal lens set in augmented reality systems and virtual reality systems for rapidly varifocal images and vision correction

The major challenges of augmented reality (AR) systems and virtual reality (VR) systems are varifocal images for vergence-accommodation conflict (VAC) and vision corrections. In this paper, we design a liquid crystal (LC) lens set consisting of three LC lenses for varifocal images and vision corrections in AR and VR. Four operating modes of such a LC lens set present three electrically tunable lens powers: 0, -0.79 diopters, -2 diopters, and -3.06 diopters by means of manipulation of polarization of incident light using electrically tunable half-wave-plates. The response time is fast(< 50 ms). We also demonstrate AR and VR systems by adopting the LC lens set to exhibit functions of varifocal images and vision corrections which enable to solve VAC as well as vision problem in AR and VR.