基于已有的单圆孔电极液晶透镜的结构与设计方法,研制了新型的电控可变焦128元×128元液晶微透镜阵列.该面阵液晶微透镜使用氧化铟锡(ITO)玻璃作为上下基板,上电极通过光刻技术和盐酸腐蚀方法得到128元×128元圆孔阵列图案;下电极为ITO膜.上电极的圆孔阵列排列整齐,每个圆孔的直径为50 μm,圆孔之间的间隔为100 μm,夹在上下基板之间的液晶层的厚度为20 μm.验证了该面阵液晶微透镜的光学特性,结果表明,在0.2～5.0 V(RMS),该面阵液晶微透镜的焦距为50～400 μm,焦点的焦斑尺寸在10 μm左右,点扩展函数值近似于理论数值.该面阵液晶微透镜的工作电压与焦距成反比,可以成清晰的多重像.%A new electrically driving and controlling 128 element × 128 element Liquid Crystal (LC) micro-lens array with tunable focal length is proposed based on the structure and design methods of a single circular hole electrode LC lens.The Indium Tin Oxide (ITO) glasses are used as the top and bottom substrates of the LC micro-lens array.The top electrode patterns containing 128 element×128 element are obtained by a lithography and a hydrochloric acid etching,in which every element is a single circular hole of 50 μm diameter and the distance between the two circular holes is 100 μm.The bottom electrode is just the ITO film.Furthermore,the thickness of LC layer between the top and the bottom electrodes is about 20 μm and the focal length of the LC micro-lens array can be electrically tuned from 50 μm to 400 μm under the operating voltage from 0.2 V (RMS) to 5.0 V(RMS).The result of the test indicates that the point spread function of the LC micro-lens array is close to the theory value,and the relationship of operating voltage and focal length is in an inverse proportion.These results show that the imaging characteristic of the LC micro-lens array can be comparable to those of the conventional optical micro-lens arrays.
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