Chang Sung-Il, Yoon Jun-Bo
Opt Express. 2004 Dec 13;12(25):6366-71. doi: 10.1364/opex.12.006366.
This paper describes a simple and effective method to fabricate a plastic microlens array with controllable shape and high fill-factor, which utilizes the conventional lithography and plastic replication. The only difference from conventional lithography is the insertion of a diffuser that randomizes paths of the incident ultraviolet (UV) light to form lens-like 3D latent image in a thick positive photoresist. After replication of the developed concave microlens mold onto the polydimethylsiloxane (PDMS), the focal length of the fabricated hemispherical microlens was observed to be 13-88 microm depending on the UV exposure dose. Two PDMS curing conditions were tested, where the elevated temperature of 85 masculineC resulted in smoother surface roughness of 2.6 nm in RMS value in the microlens mold. The proposed method can be extensively applied for microlens fabrication with other plastic materials due to its simplicity and versatility.
本文描述了一种利用传统光刻和塑料复制技术制造形状可控、填充因子高的塑料微透镜阵列的简单有效方法。与传统光刻的唯一区别在于插入了一个扩散器，该扩散器使入射紫外（UV）光的路径随机化，从而在厚正性光刻胶中形成类似透镜的三维潜像。在将显影后的凹面微透镜模具复制到聚二甲基硅氧烷（PDMS）上后，观察到制造的半球形微透镜的焦距根据UV曝光剂量在13 - 88微米之间。测试了两种PDMS固化条件，其中85摄氏度的高温导致微透镜模具的表面粗糙度在RMS值上更平滑，为2.6纳米。由于其简单性和通用性，所提出的方法可广泛应用于用其他塑料材料制造微透镜。
