为提高变折射率平面微透镜阵列的填充率, 利用光刻工艺和离子交换技术制备了填充率近达100%的方形孔径平面微透镜阵列, 并对其透镜元及相邻透元间间隙构成的角落区域的成像进行了理论和实验研究.根据变折射率介质光线追迹法, 利用MATLAB软件模拟, 发现在透镜元区域和角落区域成像特性相反.成像系统测试表明: 由于透镜元区域和角落区域的折射率分布变化规律不同, 透镜元与角落区域对物体分别成倒立实像和正立虚像；透镜阵列可实现聚焦和散焦功能；角落区域得到充分的离子交换使得间隙足够小, 形成了从该区域中心向外逐渐增大的新型梯度折射率模型.

To improve filling factor of planar microlens arrays, square-aperture planar microlens arrays with good performance was fabricated with photolithography and thermal ion-exchanging technology, their fill factors was 100%. Imaging characteristics of unit lens and region among the four adjacent lens units (be called corner area) of square-aperture planar microlens arrays were analyzed theoretically and experimentally. Imaging characteristics in corner area are reverse to those in focusing element lens, which is showed by ray tracing and MATLAB simulation. Results with image testing system show that a reversed real image of object is formed after the ray passes through unit lens, while an erect virtual image is obtained because of divergent light out from corner area, which is caused by different refractive index distribution in these two areas. Therefore, square-aperture planar microlens arrays achieve the function of focusing and defocusing. Moreover, with enough ion-exchanging time, the uniform refractive index region in the corner area is so little that a new-type gradient refractive distribution is formed which increases gradually out from the center.