基于纳米压印的大角度衍射光学元件批量化制备方法

Fabrication of Large-angle Diffractive Optical Element Based on Nanoimprint Lithography

针对大角度(大于50°)衍射光学元件低成本、批量化制备的需求,提出一种基于纳米压印技术的制备方法.首先利用光学曝光技术或电子束直写技术制备衍射元件的原始母板,然后将原始母板的结构通过纳米压印过程复制到压印胶上,完成衍射光学元件的制备.由于纳米压印母板可以多次重复使用,降低了制作成本,提高了效率.用该方法制备了不同特征尺寸(最小为250nm,衍射全角为70°)的衍射光学元件,具有良好的衍射效果,实现了对高深宽比浮雕结构的高保真复制.该技术可实现从微米到纳米跨尺度兼容的衍射光学元件的高保真、低成本、批量化制备.

In order to fabricate the large-angle（more than 50°）diffractive optical elements with low cost and mass preparation,a fabrication method base on nanoimprint lithography was proposed.A diffractive optical elements master mold was prepared via conventional photolithography or electron beam lithography.The mold was then imprinted onto the nanoimprint resist with quartz substrate.The structure was transferred to the resist and the diffractive optical elements were achieved.In contrast to other techniques,the nanoimprint mold can be repeatedly used to lower production cost and improve the efficiency.Based on the method,diffractive optical elements with different feature sizes（minimum 250 nm,diffractive angle 70°）were fabricated for different diffractive patterns,which has a good diffractive efficiency,realizing high-fidelity replication of relief structure with high aspect ratio.The technology can fabricate diffraction optical elements from micron to nanometer scale with high fidelity,low cost and mass production.