Electrically Tunable-Focusing Liquid Crystal Microlens Array with Simple Electrode

Abstract

An electrically tunable-focusing liquid crystal (LC) microlens array exhibiting a wide-range tunable focal length is proposed. The lower substrate has strip indium tin oxide (ITO) electrodes, the upper substrate has periodic ITO electrodes with a certain gap coated on the inner surface., and an LC microlens is generated between the two strip electrodes. For each LC microlens, the gap between the top planar electrodes is directly above the center of the microlens. Unlike the conventional LC lens, the individual LC microlens is not coated with ITO electrodes on the central part of its upper and lower substrates, which helps to maintain the LC’s horizontal orientation. In the voltage-off state, the focal length of the microlens array is infinity because of the homogeneous LC alignment. At a given operating voltage, an ideal gradient refractive index distribution is induced over the homogeneous LC layer, which leads to the focusing effect. The simulation result shows that the focal length of the LC microlens could be gradually drawn to 0.381 mm with a change of voltage.

Tunable Liquid Lenses: Emerging Technologies and Future Perspectives

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Building a DC electric field-driven wheat leaf-like surface pattern with a cholesteric liquid crystal fluoropolymer for directional droplet manipulation

“…4, these nonuniform electric potential distributions between adjacent strip electrodes will render LC molecules to be reorientated and reduce their order parameter. [42][43][44] A very keen competition exists between the orientation produced by the surface anchoring and by the electric field effects. 32 Meanwhile, it will be further enhanced by the limitation of a cross-linking network and a steric hindrance effect throughout the rearrangement of LC units.…”

Achromatic polymer-dispersed liquid crystal lens with diffractive–refractive hybrid structure

“…Nematic Liquid Crystals (NLCs) have anisotropic and birefringent properties [1,2]. The orientation of LC molecules can be controlled by the voltage applied to the pixelated electrodes, which can generate gradient refractive index profiles induced by an electric field to achieve an electronically controlled zoom function [3,4]. Due to the advantages of strong light transmission, low power consumption, high reliability, simple control and small size, LC microlenses are widely used in daily life and industrial production.…”