电控聚合物分散液晶变焦全息透镜制作

介绍了相位型全息聚合物分散液晶(PDLC)材料全息透镜,在电场作用下液晶微滴折射率逐渐与聚合物折射率匹配,实现透镜电控变焦。研究了微米尺寸和纳米尺寸液晶微滴聚合物分散液晶材料配方特性和微观结构。采用优化纳米尺寸材料配方制作5~6μm聚合物分散液晶盒,采用离轴式平面波和球面波干涉全息写入光路,成功制作电控变焦聚合物分散液晶全息透镜样品。该透镜样品焦距为20 mm,能够正一级衍射放大成像。实现“0”,“1”变焦的驱动电压阈值为60 V。并进一步提出了基于聚合物分散液晶电控变焦元件集成叠加技术实现电控变焦光学成像系统的技术思路。

Fabrication of Electrical-Controlled Polymer Dispersed Liquid Crystal Switchable-Focus Holographic Lens

When ac voltage is applied, the refractive indexes of liquid crystal droplets and polymer binders match gradually, and the phase-type electrical-controlled switchable focus lens based on polymer dispersed liquid crystal (PDLC) material is switched on and off . In experiments, recipes and characteristics of micrometer size and nano-scale size polymer dispersed liquid crystal materials have been researched. The newly developed optimized nano-scale liquid crystal droplets polymer dispersed liquid crystal recipe is adopted to fabricate polymer dispersed liquid crystal cell samples with thickness of 5～6 μm. And in plane wave and spherical wave interference optical recording system, primary off-axis polymer dispersed liquid crystal focus-switchable holographic lens sample is developed with focal length of 20 mm. Amplified images with positive one-order diffraction are achieved and the driving voltage threshold for “0”, “1” transfer is about 60 V ac voltage. Furthermore, the conception of electrical-controlled focus-switchable optical image system based on polymer dispersed liquid crystal focus-switchable lens integration is put forward.