The Hong Kong University of Science and Technology

Abhishek Kumar Srivastava

Hoi Sing Kwok

Zhengnan Yuan

Zhibo Sun

Hoi-Sing Kwok

Valerii Vladimirovich Vashchenko

Swadesh Kumar Gupta

Chengbin Kang

Olena V Vashchenko

Yiyang Gao

Maksym Fedorovich Prodanov

Yuechu Cheng

A ferroelectric liquid crystal (FLC) material for the deformed helix FLC (DHFLC) electro-optical mode devices and shows optimum electro-optical properties including high tilt angle (>38°), and short helix pitch (<120 nm), and spontaneous polarization (>100 nC/cm) comprising at least two components, wherein at least one FLC component is a chiral compound of Formula (I): particularly: wherein Wand Ware chiral groups with polar substituent at chiral centre, A and B are independently N atom or CH groups providing that at least one of A or B is N atom. Other various groups are as defined herein.

Compound and liquid crystal composition

A switchable liquid crystal grating cell, and methods for manufacturing the above. The switchable liquid crystal grating cell comprises a pair of switchable liquid crystal grating parts, each switchable liquid crystal grating part comprises a substrate; a conductive layer on the substrate; and a photoalignment layer with an alignment pattern above the conductive layer on the substrate, the alignment pattern having first and second types of domains, the first type of domain having a first uniform alignment direction, the second type of domain having a second uniform alignment direction that is reoriented at a predetermined angle to the first uniform alignment direction, the predetermined angle is 85°-95°, and a liquid crystal layer sandwiched between the pair of switchable liquid crystal grating parts, wherein an alignment pattern on a top surface is arranged to be shifted relative to the other alignment pattern on a bottom surface.

Electrically switchable liquid crystal grating cell based on photoalignment with an amplitude mask

Various photo-luminescent films and associated methods are enabled. For instance, a photo-luminescent film comprises a substrate layer comprising a plurality of pores, and a composite comprising luminescent nanoparticles disposed in the plurality of pores.

Stable photo luminescence porous films

One or more devices, systems, methods and/or apparatus to facilitate suppression of fringe field effect, such as for diffraction grating and/or display purposes. In one embodiment, a ferroelectric liquid crystal (FLC) element can comprise a pair of conductive substrates, a FLC layer having a helical pitch and positioned between the conductive substrates, one or more spacers fixedly positioned between the conductive substrates, and an alignment layer positioned between the FLC layer and one of the conductive substrates. The alignment layer can be disposed at least partially contiguous with the FLC layer. The FLC layer can comprise a chiral smectic C* liquid crystal layer having at least one of a helical pitch smaller than an average cell gap of the FLC layer, or an average helical pitch of the FLC layer being smaller than an average thickness of the FLC layer between the conductive substrates.

High-contrast ferroelectric liquid crystal cell

Techniques for using ferroelectric liquid crystals Dammann grating (FLCDG) for light detection and ranging devices are disclosed. In LiDAR devices, accuracy, response time, and cost performance can be limited by some factors, such as laser pulse width, time resolution of a time-to-digital conversion chip, detector bandwidth, shot noise, and time error generated by electronic circuits. A FLCDG-based architecture can improve a LiDAR device, and provide for one-shot capturing due to the high switching speed at very low driving voltage provided by ferroelectric liquid crystals and the equal diffracting ability of Dammann grating.

Growing community of inventors

Hong Kong, China

Abhishek Kumar Srivastava