Research On Polarization-independent Liquid Crystal Lens

Liquid crystal lens is a tunable-focusing lens,based on an external voltage to achieve the gradient refractive index distribution of liquid crystal layer.Therefore,liquid crystal lens can modulate the phase of incident light.Compared with traditional optical lens,liquid crystal lens has the advantages of adjustable focal length,small size,low cost,easy integration and so on,which is widely used in various optoelectronic devices.Based on the application of liquid crystal lens in zoom glasses,this paper is aimed to solve the problem of large aperture and polarization-independent of liquid crystal lens in zoom glasses.On the one hand,the mode control structure is used to solve the problem of no voltage change in the central region of large aperture liquid crystal lens.The voltage gradually decreases from the edge of the circular hole to the center by preparing a high resistance layer on the surface of the lens circular hole,forming a parabolic phase distribution.On the other hand,a double-layered liquid crystal lens with mutually perpendicular alignment is used to achieve polarization-independent characteristics,and two liquid crystal lenses respectively modulate with mutually perpendicular linearly polarized light.The mode control structure of liquid crystal lens is simulated,and the influence of the frequency of applied voltage,the resistance of high resistance layer and the capacitance of liquid crystal layer on the surface voltage distribution of the lens hole is studied.After completing the process of preparing liquid crystal lens,the effect of high resistance film made of PEDOT:PSS and ZnO on the performance of the lens is compared,and polarization-independent liquid crystal lens is prepared with ZnO as the high resistance layer.The optical experiment platform is built to test the performance of the lens.The test results show that the different apertures size of liquid crystal lens larger than 1mm can achieve tunable-focusing imaging.A liquid crystal lens with a maximum aperture of 10 mm has a minimum focal length of 0.825 m.Under different polarized light,measuring the normalized light intensity value of double-layered mode control liquid crystal lens and observing its imaging effect,the results show that both of them do not change with the different polarization degree,which verifies the polarization-independent characteristics of double-layered mode control liquid crystal lens.In terms of optical path difference distribution,wavefront error and imaging,the imaging quality of the large aperture liquid crystal lens is evaluated,and the driving condition is optimized.Finally,a preliminary test of zoom glasses is carried out on a liquid crystal lens with an aperture of 10 mm.The results show that the subjects with hyperopia can clearly observe the image of object after passing through liquid crystal lens,and after changing the frequency of the applied voltage,the image of object observed by the subject changes from blurry to clear or clear to blurry,which lays an important foundation for the application of large aperture polarization-independent liquid crystal lens in the zoom glasses.