Optimization of liquid crystal devices based on weakly conductive layers for lensing and beam steering

Abstract

Liquid crystals are mostly known for their use in displays, but over the past decade these materials have been applied in a number of other devices such as tunable lenses or beam steering devices. A common technique to realize a gradual electric field profile as is required to obtain a gradual refractive index profile in these applications is the use of weakly conductive materials. The weakly conductive layers are able to spread the voltage profile which is applied through well-conductive electrodes at the side of the weakly conductive layer. The simulation and design of such structures is not trivial because two or three dimensional quasi-static electric field profiles need to be calculated. This is due to the fact that the resistivity of the conductive layers and the dielectric properties of the liquid crystal are coupled. An exact solution requires solving a number of coupled differential equations. In this paper, we develop a model to simulate the RC-effects with an approximate model

Compact, fast‐response, continuous, and wide‐angle laser beam steerers

“…Previously, many have reported that an almost linear refractive index change can be established across the resistive electrode by carefully choosing the resistive materials. [17][18][19] In this case, light direction change is no longer caused by refracting through discrete refractive index contrast interfaces, but by continuous phase gradient accumulation. As we will discuss later, the advantage of using resistive electrode is its potential to reduce the form factor of the device.…”

“…This is achieved by applying a high voltage on the bottom conductive electrode. Previously, many have reported that an almost linear refractive index change can be established across the resistive electrode by carefully choosing the resistive materials 17–19 . In this case, light direction change is no longer caused by refracting through discrete refractive index contrast interfaces, but by continuous phase gradient accumulation.…”

Liquid Crystal Beam Steering Devices: Principles, Recent Advances, and Future Developments

“…This approach mainly suffered from the flyback region effect and a non-ideal phase gradient, along with other concerns with regards to increased power consumption resulting from the resistive electrodes. Nevertheless, to improve the phase gradient, a device optimization method has been developed [52].…”

Термомеханический Режим Формирования Вихревых Течений В Гибридно Ориентированном Нематическом Канале

“…В последнее время все чаще методы микро-и нанофлуидистики находят применение не только при исследовании процессов транспортировки и сортировки нанолитровых объемов молекулярных жидкостей [1][2][3][4], но и в разнообразных семействах сенсоров и датчиков на основе термо-и лиотропных жидкокристаллических (ЖК) материалов [3,5]. Еще одной не менее интригующей областью применения микролитровых объемов ЖК-материалов являются биометрические оптические системы, где основным элементом являются ЖК-линзы с регулируемым фокусным расстоянием (tunable liquid crystal microlenses) [6,7]. Один из способов, позволяющий манипулировать такими микроразмерными молекулярными системами, основывается на использовании электрического поля [8].…”