Low aberrations symmetrical adaptive modal liquid crystal lens with short focal lengths

Abstract

We describe the design, fabrication, and characterization of modal liquid crystal lenses (MLCLs) with a symmetrical electrode structure using a resistive composite polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS). We achieved MLCLs with shorter focal lengths (up to 1cm), shorter apertures (1 to 5mm), and lower aberrations compared to other MLCLs. We demonstrate a very uniform conductivity distribution in the PEDOT-PSS layers over a wide resistivity range (100kOmega/sq-10MOmega/sq) combined with a symmetrical electrode structure, enabling us to manufacture MLCLs with short f-numbers, large depths of focus, and low aberrations.

Liquid-crystal photonic applications

“…The simplest approach is to pattern the transparent conductor in a way that a Fresnel-type lens is obtained with different zones of the liquid-crystal that are alternatively switched and not switched. 46 This approach however requires accurate fabrication of the electrode pattern. As an alternative approach, the combination of a weakly conductive layer in combination with a hole-patterned electrode can also produce a spatially dependent electric field across the LC layer.…”

Electrooptic Characterization of Tunable Cylindrical Liquid Crystal Lenses

“…Naumov et al [8]. This technique consists of generating a radial graded refractive index across each lens of the array by using a layer of high resistance sheet (M /sq), deposited onto the pattern electrode, as a control electrode [9,10]. In this work, we have proposed a special mask electrode pattern (comb interdigitated) for a tunable cylindrical lenticular lens array with modal control.…”

Liquid Crystal Focusing Device

“…Thus, it was shown [9] that by changing control modes the modal LC lenses can be used for generation of inclined and astigmatic wavefronts and for implementation of controlled axicons. Due to the use of new resistive coating and alteration of geometry the decrease of focal distance of liquid crystal lenses was achieved [10]. Use of two high-resistive layers and six contact electrodes allows implementing two-dimensional array of modal LC lenses -micro-axicons, parameters of which can be controlled on the basis of applied voltage, to the authors [11,12].…”

“…Так, было показано [9], что изменяя режимы управления, модальные ЖК-линзы можно использовать для формирования наклонных и астигматических волновых фрон-тов, а также для реализации управляемых акси-конов. За счет использования нового резистив-ного покрытия и изменения геометрии удалось добиться уменьшения фокусного расстояния жид-кокристаллических линз [10]. Использование двух высокорезистивных слоев и шести контактных электродов позволило авторам [11,12] реализовать двумерную матрицу модальных ЖК линз -микро-аксиконов, параметрами которых можно управ-лять в зависимости от прикладываемого напря-жения.…”