A New Dual-Frequency Liquid Crystal Lens with Ring-and-Pie Electrodes and a Driving Scheme to Prevent Disclination Lines and Improve Recovery Time

Kao, Yung Yuan; Chao, Paul C.-P.

doi:10.3390/s110505402

Cited by 29 publications

(8 citation statements)

References 35 publications

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“…Several approaches have been proposed to improve the response time. Dual frequency LCs (DFLCs), which exhibit a positive dielectric anisotropy (Δε) at low frequencies and negative Δε at high frequencies, have been adopted to speed up both rise and decay times of an LC device by controlling the applied frequency [36,39,40]. However, the driving scheme is relatively complicated, and dielectric heating may shift the crossover frequency and lead to performance instability at high frequency operation [41].…”

Section: Introductionmentioning

confidence: 99%

Fast-Response Liquid Crystal Microlens

Liu

et al. 2014

Micromachines

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Electrically tunable liquid crystal microlenses have attracted strong research attention due to their advantages of tunable focusing, voltage actuation, low power consumption, simple fabrication, compact structure, and good stability. They are expected to be essential optical devices with widespread applications. However, the slow response time of nematic liquid crystal (LC) microlenses has been a significant technical barrier to practical applications and commercialization. LC/polymer composites, consisting of LC and monomer, are an important extension of pure LC systems, which offer more flexibility and much richer functionality than LC alone. Due to the anchoring effect of a polymer network, microlenses, based on LC/polymer composites, have relatively fast response time in comparison with pure nematic LC microlenses. In addition, polymer-stabilized blue phase liquid crystal (PS-BPLC) based on Kerr effect is emerging as a promising candidate for new photonics application. The major attractions of PS-BPLC are submillisecond response time and no need for surface alignment layer. In this paper, we review two types of fast-response microlenses based on LC/polymer composites: polymer dispersed/stabilized nematic LC and polymer-stabilized blue phase LC. Their basic operating principles are introduced and recent progress is reviewed by examples from recent literature. Finally, the major challenges and future perspectives are discussed. OPEN ACCESSMicromachines 2014, 5 301

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Section: Introductionmentioning

confidence: 99%

Fast-Response Liquid Crystal Microlens

Liu

et al. 2014

Micromachines

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“…[1][2][3]. Several practical LC techniques, such as zone-patterned structures [4], hole or hybrid-patterned electrodes [5][6][7][8][9], and inhomogeneous polymer networks [10], have been proposed for lens fabrication.…”

Section: Introductionmentioning

confidence: 99%

A Fast-Response and Helicity-Dependent Lens Enabled by Micro-Patterned Dual-Frequency Liquid Crystals

Duan

Chen

et al. 2019

Crystals

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Liquid crystals are excellent candidates for tunable optical elements due to their large birefringence and continuous tunability by external fields. A dual-frequency liquid crystal lens integrated with Pancharatnam–Berry phase was fabricated via a dynamic photo-patterning technique. The proposed lens exhibited distinctive polarization-dependent characteristics and ultra-high efficiency rates of up to 95%. Via merely alternating the frequency of the applied electric field, the switching time between unfocused and focused states was measured in submilliseconds. This work supplies a new strategy for fast-response, high-efficiency and helicity-dependent lens with merits of easy fabrication and low power consumption.

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“…For example, the disclination line is a common issue, owing to discontinuous LC orientation induced by the fringe electric field [23]. Several approaches have been implemented to prevent this issue including polymer-stabilized LCs on substrate surfaces [24], applying an additional electric field in cells [25,26], and adding an insulator layer between the LC layer and the electrode in cells [12,27].…”

Section: Introductionmentioning

confidence: 99%

An Electrically Tunable Liquid Crystal Lens with Coaxial Bi-Focus and Single Focus Switching Modes

Chien

Sheu

2017

Crystals

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A hole-patterned electrode liquid crystal (LC) lens with electrically switching coaxial bi-focus and single focus modes of tuning is demonstrated. The proposed LC lens mainly consists of a two LC layer (TLCL) structure with different thicknesses to achieve higher focusing power than the conventional hole-patterned electrode LC lens with the same aperture size. In the TLCL structure, one LC layer, doped with 3 wt % RM257, was photopolymerized to achieve a fixed focusing power of 18.5 Diopter. Due to polarization dependence in TLCL lenses, an additional 90 • twisted nematic (TN) cell was used to change the incident polarization in order to switch lens functions on or off. As a result, a fixed focusing power of 18.5 Diopter was achieved when voltages of 10 V rms were applied to the 90 • TN cell. In addition, the switching capabilities of the bi-focus and single focus modes were achieved when operating individually with applied voltages from 20 V rms to 90 V rms , and higher voltages of over 90 V rms , respectively. The maximum focusing power in the fabricated TLCL lens is 30.9 Diopter.

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A New Dual-Frequency Liquid Crystal Lens with Ring-and-Pie Electrodes and a Driving Scheme to Prevent Disclination Lines and Improve Recovery Time

Cited by 29 publications

References 35 publications

Fast-Response Liquid Crystal Microlens

Fast-Response Liquid Crystal Microlens

A Fast-Response and Helicity-Dependent Lens Enabled by Micro-Patterned Dual-Frequency Liquid Crystals

An Electrically Tunable Liquid Crystal Lens with Coaxial Bi-Focus and Single Focus Switching Modes

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