本研究利用Twyman-Green干涉儀對於電控調制焦距之液晶透鏡進行其球面像差表現之評估，並與玻璃透鏡的結果做比對。
若待測物無像差，其Twyman-Green干涉圖應為整面無干涉條紋的狀況，而藉由比較Twyman-Green干涉圖後得知：玻璃透鏡本研究量測系統中像差幾乎可以忽略。而本實驗室製作之圓孔型電極液晶透鏡(Hole-Patterned Electrode Liquid Crystal Lens, HPELCLs)則是在不同電壓下有不同程度的球面像差。
為了明確比較液晶透鏡與玻璃透鏡的球面像差，本研究亦將兩者放入Mach-Zehnder干涉儀觀測其菲涅爾區圖案，發現無球面像差的玻璃透鏡可觀察到菲涅爾區圖案，而有球面像差的液晶透鏡則不行。
為了解液晶透鏡球面像差問題，本研究提出利用觀察Twyman-Green干涉圖並使用光圈限縮入射光照射在液晶透鏡的面積，選出無球面像差的區域。利用此方法，成功紀錄了4 mm、3 mm和2 mm圓孔孔徑液晶透鏡的菲涅爾區圖案。

This research presents an optical evaluation of spherical aberration in Hole-Patterned Electrode Liquid Crystal Lenses (HPELCLs) through interferogram analysis using a Twyman-Green interferometer. This study investigates the optical characteristics of electrically tunable liquid crystal lenses, with an emphasis on comparing their spherical aberration to that of traditional glass lenses. Through Twyman-Green interferogram and Fresnel zone pattern observations, we provide a comprehensive framework for identifying and mitigating spherical aberrations in HPELCLs.
Initial interferometric analyses revealed that the glass lenses introduced negligible aberration under experimental conditions. In contrast, HPELCLs demonstrated various degrees of spherical aberration depending on the applied voltage. To resolve this problem, we developed a methodology to decide aberration-free regions within the liquid crystal lens aperture by using iris of varying diameters. Through this method, regions of HPELCLs with relatively uniform refractive index gradients were selected, allowing the successful recording of Fresnel zone patterns.
By selectively illuminating aberration-free regions, we successfully generated Fresnel zone patterns with single HPELCLs, previously unachievable without the aid of conventional lenses. These findings contribute to the broader understanding of tunable liquid crystal optics and open pathways for developing high-performance electro-optical devices using compact and adaptive lens systems.

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