A thin multi-ring negative liquid crystal lens enabled by high-κ dielectric material

Abstract

This study is dedicated to design an liquid crystal (LC) negative lens with unequal width electrodes, which is made for a camera lens and with the aim to replace conventional negative lenses. The structure of the LC negative lens is symmetric for producing a symmetrical electric field. The unequal widths are adopted and determined inversely proportional to the slopes of the desired applied voltages at varied radial positions. There are four ring electrodes in the lens and the associated with applied different voltages. In addition, the performance of the designed LC lens is verified by the software DIMOS.2D. The special structure and the material are used to realize the designed LC lens. Moreover, a new fabrication process in the wafer level to bury bus lines is developed in order to smooth the generated electric field distribution. In addition, a high-j dielectric layer is coated between the electrodes and the LC layer for minimizing required applied voltage. Finally, differential effects of the LC lens structure with high-j and without high-j are discussed based on simulation results.

A Review of Electrically Tunable Focusing Liquid Crystal Lenses

“…The aberration and the image quality of the LC lenses are determined by the distribution of the electric fields. For precisely controlling the distribution of the electric fields, the pixelated electrode design is a way to control the electric fields pixel by pixel [64][65][66][67][68][69][70]. The larger numbers of the electrodes have, the better image quality of the LC lenses can have.…”

“…cent electrodes can simplify the driving scheme and provide the smooth distribution of electric field [65][66][67]. The image quality and diffraction efficiency can be improved by dividing electrodes into two groups: odd and even electrodes, and then two groups are separated by the silicon oxide [65][66][67][68][69][70]. The gap between adjacent electrodes can be ignored and thus increase the diffractive efficiency and tolerance of the line width.…”

Dual layer electrode liquid crystal lens for 2D/3D tunable endoscopy imaging system

“…To further improve the optical performance of LC lens, high-dielectric layer [16,17] was used to smooth the phase profile across the lens without attenuating much electrical potential. However, high-dielectric layer increases the operating voltage to higher than 30volts.…”

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

“…A hole-patterned indium-tin oxide (ITO-) electrode along with a counter-electrode were presented later on an LC lens by [ 6 ] to generate a non-uniform electrical field for focusing effects. Following [ 6 ], there were a number of works [ 6 – 18 ] presenting variations of LC lens designs with different electrode shapes, like circular, cylindrical, and hexagonal-hole-patterned ones. Some others adopted the design principle of the Fresnel zone plate [ 19 , 20 ], but rendering less focusing power from higher-order focused lights.…”

“…It is known that due to the thick LC layer [ 6 – 18 ] required to ensure enough focusing power in CCMs, the recovery time of the LC lens is generally very slow [ 30 ], and usually exceeds ten seconds. One remedy is to apply a high initial voltage.…”