Ultra-precision patterned microstructures, including freeform surfaces by superimposing microstructures, are widely adopted in optical applications, such as three-dimensional (3D) imaging, micro-optical telescopes, confocal microscopy, endoscope systems, and machine vision,^1–5 to realize the specified optical performance and a compact system. Such kind of compound surfaces can be fabricated through various approaches. For example, microlens array on a curved surface was fabricated by transferring the pattern to another polymeric template which was then deformed by negative pressure.⁶ Other methods are found to fabricate microlens arrays such as quartz wet etching.⁷ However, these methods are either of complex process, lack of feasibility of form control, or in a low precision which is not applicable for optical applications.

中文翻译：

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超精密复合自由曲面的生成和表征

超精密图案化微结构，包括通过叠加微结构形成的自由曲面，广泛应用于光学应用，例如三维（3D）成像、微型光学望远镜、共焦显微镜、内窥镜系统和机器视觉，^1-5指定的光学性能和紧凑的系统。这种复合表面可以通过多种方法制造。例如，通过将图案转移到另一个聚合物模板上，然后通过负压使该模板变形来制造弯曲表面上的微透镜阵列。⁶人们还发现了其他制造微透镜阵列的方法，例如石英湿法蚀刻。⁷然而，这些方法要么工艺复杂，缺乏形状控制的可行性，要么精度低，不适用于光学应用。