Research On Methods Of Enhancing Image Performance Of Liquid Crystal Lens

Liquid crystal lens is a new type of optical lens that can change the effective refractive index distribution in the lens by regulating the electric field distribution in the lens to achieve the zoom effect.Compared with traditional optical lenses,it has the advantages of small size,light weight and adjustable focus.Liquid crystal lens is of great interest in the field of optical lenses.First,this study proposes an electrode optimization method for the problem of electric field fluctuation near the edge of conventional liquid crystal lens with circular hole electrode and the following results were obtained by numerical simulation: the average value of the maximum fluctuation of the pointing vector of liquid crystal molecules is 42.41° near the edge of the three directional cross-sections of the liquid crystal lens before optimization.The corresponding value of the electrode-optimized lens is 13.44° and it decreased by 28.87°compared to the pre-optimization lens.It effectively improves the problem of electric field fluctuation at the edge of lens.Secondly,a new electric field control method is designed to solve the problem of image quality degradation of high resistance layer electrode liquid crystal lens at high optical focal length: optimizing the spacing distribution of high resistance layer and lower electrode layer to form a new curved high resistance layer electrode.The following are the results of image quality evaluation before and after lens optimization: in the optical power of 10.67 D～13.77 D,the root mean square radius of dispersion circle of liquid crystal lens with curved high resistance layer electrode ranges from 10.8 μm～29.8 μm,which is a significant decrease compared to the range of 77.1 μm～94.6 μm before optimization.In most cases,it is also lower than the corresponding value of 26 μm for a double Gaussian lens.The designed liquid crystal lens with curved high resistance layer electrode has a wavefront root mean square error range of 0.07 μm～0.11 μm and the corresponding range of the contrasted lens is 0.11 μm～0.14 μm.The image quality evaluation shows that the designed liquid crystal lens with curved high resistance layer electrode has high image quality at high optical power.Finally,the lens with orthogonally oriented double liquid crystal layer and high resistance layer electrode is proposed for soving problem of strong dependence on light polarization of liquid crystal lens.The numerical simulation shows that it has twice optical power than the high resistance layer electrode lens with single liquid crystal layer at the same effective voltage.The response times of the designed liquid crystal lens is almost the same as that of the high resistance layer electrode lens with single liquid crystal layer.This shows that the designed liquid crystal lens has the advantages of independent of light polarization,high optical power,low driving power and fast zoom response.