En-Wei Zhong

1D/2D switchable grating based on field-induced polymer stabilized blue phase liquid crystal

We present a 1D/2D switchable grating based on field-induced polymer stabilized blue phase liquid crystal (PSBPLC). For 1D grating, the diffraction efficiency of the first order is 37.2% and the phase modulation depth of the 1D grating can achieve 2π. For 2D grating, more than 90% of light intensity is distributed to the surrounding orders of zero order and the phase modulation depth is about 3.67π. Furthermore it shows fast phase modulation and 1D/2D switching time.

Improved Kerr constant and response time of polymer-stabilized blue phase liquid crystal with a reactive diluent

A polymer-stabilized (PS) blue phase liquid crystal (BPLC) with fast response time and large Kerr constant is investigated by doping a low molecular weight monomer (N-vinylpyrrollidone) into a conventional PS-BPLC consisting of BPLC, RM257, and 1,1,1-trimethylolpropane triacrylate. With this polymer network system, Kerr constant and the response can be improved simultaneously. Compared to the conventional PS-BPLC, Kerr constant of the proposed PS-BPLC can increase by 54% and the response time can decrease by 23% at the same time. The contrast ratio can be kept at a high level, over 1000:1 at λ = 633 nm.

Critical temperature in phase transition of blue phase liquid crystal

A critical temperature is found in the phase transition of blue phase liquid crystal (BPLC), which affects the electro-optical properties and polymer stabilization of polymer stabilized BPLCs (PSBPLCs). The relation between lattice formation process of BPLCs and the temperature is also demonstrated showing that the heterogeneous lattice generation and the homogeneous lattice growth dominate the different temperature ranges in phase transition process. With different cooling rates, the material properties of BPLCs change as the result of different stages of heterogeneous lattice generation and homogeneous lattice growth.

A Transflective Display Using Blue Phase Liquid Crystal

A combined fringe and in-plane switching (FIS) mode single-cell-gap transflective display using blue-phase liquid crystal (BPLC) is proposed. The structure makes use of the space above the pixel electrodes of this FIS mode as reflective regions and the space between pixel electrodes as transmissive regions. The structure which can be optimized to balance the optical phase retardation between transmissive region and reflective region with simple fabrication process exhibits relatively high optical efficiency and well matched voltage of transmittance and reflectance curves.