Microforging technique for rapid, low-cost fabrication of lens array molds
Microforging technique for rapid, low-cost fabrication of lens array molds
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DOI：
10.1364/ao.46.008668
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发表时间：
2007-12-20
期刊：
影响因子：
1.9
通讯作者：
Hunter, Ian W.
中科院分区：
文献类型：
--
作者：
Forest, Craig R.;Saez, Miguel A.;Hunter, Ian W.
对用于从电信到生命科学的应用的微光学元件的兴趣推动了对可获得的低成本制造技术的需求。许多微透镜制造工艺不适合于需要100%填充因子、具有高数值孔径的类似于1000 μ m的孔径以及大面积可缩放性（例如，几十厘米到几米），具有数百万个透镜。我们报告了一种灵活的，低成本的模具制造技术，利用铣削和微锻造相结合。该技术涉及首先执行一个粗略的削减与球端铣刀。然后，通过将等直径的球体压入研磨过的模具中来实现最终形状和下垂高度。利用这种方法，我们已经制造了1- 10，000个透镜的矩形阵列的模具，其孔径为25-1600 μ m，下垂高度为3-130 μ m，透镜间间距为250-2000 μ m，填充因子高达100%。模具轮廓具有68 mn和354 mn的粗糙度和图形误差，分别为100%填充因子，1000 μ m孔径透镜。所需的锻造力被建模为一个修改后的开式模锻过程，并通过实验验证，以增加表面积的近线性。通过点扩散函数成像表征了微锻模具注射成型透镜阵列的光学性能，并发现其在理论值范围内。该过程也可以很容易地适用于透镜阵列。限制包括铣床范围和精度。(C)2007年，美国光学学会。
Interest in micro-optical components for applications ranging from telecommunications to life sciences has driven the need for accessible, low-cost fabrication techniques. Many microlens fabrication processes are unsuitable for applications requiring 100% fill factor, apertures similar to 1000 mu m with high numerical aperture, and scalability to large areas (e.g., tens of centimeters to meters) with millions of lenses. We report on a flexible, low-cost mold fabrication technique that utilizes a combination of milling and microforging. The technique involves first performing a rough cut with a ball-end mill. Final shape and sag height are then achieved by pressing a sphere of equal diameter into the milled divot. Using this process, we have fabricated molds for rectangular arrays of 1-10,000 lenses with apertures of 25-1600 mu m, sag heights of 3-130 mu m, interlens spacings of 250-2000 mu m, and fill factors up to 100%. Mold profiles have a roughness and figure error of 68 mn and 354 mn, respectively, for 100% fill factor, 1000 mu m aperture lenses. The required forging force was modeled as a modified open-die forging process and experimentally verified to increase nearly linearly with surface area. The optical performance of lens arrays injection molded from microforged molds was characterized by imaging the point spread function and was found to be in the range of theoretical values. The process can be easily adapted to lenticular arrays as well. Limitations include milling machine range and accuracy. (C) 2007 Optical Society of America.