Research On Liquid Crystal Lens With Adjustable Refractive Index Distribution

The liquid crystal lens adjusts the focal length by controlling the voltage.It has the advantages of small structure,easy integration and simple operation.It has a wide range of application value in the field of life.The refractive index distribution of the new structure liquid crystal lens proposed in this subject is flexible and adjustable,which improves the aberration correction ability of the liquid crystal lens in the optical system.From the structural design of the light hole of the pattern electrode of the liquid crystal lens,combined with the experimental simulation,the influence of the driving pattern electrode on the imaging effect of the liquid crystal lens is studied.The main research contents are briefly summarized as follows:Firstly,the elastic deformation theory of liquid crystal continuum,the working principle of liquid crystal lens and the three-dimensional finite element modeling are analyzed in detail to form a complete theoretical analysis basis and lay a solid theoretical foundation for the subsequent research work.Then,using Comsol Multiphysics simulation software,the theoretical modeling and simulation of multi-ring floating electrode liquid crystal lenses with different ring numbers are carried out.Effects of electrode liquid crystal lens on voltage distribution,refractive index distribution,and wavefront error.The results show that the voltage distribution in the aperture area of the floating electrode liquid crystal lens with eleven rings is close to the ideal lens voltage distribution,and has a good voltage distribution effect.Marechal Criterion.Then,the multi-dimensional research and analysis of the multi ring floating electrode liquid crystal lens with eleven rings are carried out to verify the optical performance of the lens,analyze the influence of the lens focal length on the voltage distribution,refractive index distribution and optical path difference distribution,and the influence of the adjustable non-complete ring driving electrode lead on the electric field interference of the complete ring floating electrode.The results show that when the focal length of the lens is set to 200 mm,the root mean square of the refractive index is 5.5×10^-3,the optical path difference is 145 nm,less thanλ/4 meet the Rayleigh criterion,and the lens has low aberration.By reducing the block resistance of high resistance film in WCL layer,the electric field interference of incomplete ring driving electrode lead to complete ring floating electrode can be reduced.In addition,the three-dimensional finite element modeling and Simulation of high resistance floating electrode liquid crystal lens is carried out.It is verified that when the block resistance of floating electrode changes between 150Ω·□^-1 and 300 MΩ·□^-1,the wavefront error of liquid crystal lens first decreases and then increases,and the wavefront error reaches a very small value at 40 MΩ·□^-1;When the thickness of the dielectric layer changes from 50 nm to 5000 nm,the block resistance of the floating electrode with the smallest wavefront error of the liquid crystal lens decreases from 50 MΩ·□^-1 to 2 MΩ·□^-1,and the optimal block resistance decreases monotonically;When the square resistance of the floating electrode is 40 MΩ·□^-1and the thickness of the dielectric layer is 250 nm,when the focal length changes from 250 mm to infinity,the maximum root mean square error of the wavefront at the wavelength of 589 nm is 0.0412μm.Less thanλ/14.Meet the requirements of Marechal criterion.