Design and fabrication of a mid-wavelength infrared Fresnel lens via liquid poly(methyl methacrylate)

作者：Tsui Chun Chao^*; Wei Hsiang Chun; Chang Wen Fa; Su Guo Dung John

来源：Journal of Micromechanics and Microengineering, 2012, 22(4): 045010.

DOI：10.1088/0960-1317/22/4/045010

Most popular materials for lenses, such as glass, have high absorption in the infrared range. Due to material restriction, infrared lenses are usually much more expensive. In this paper, we discussed a ubiquitous polymer material, poly(methyl methacrylate) (PMMA), for mid-wavelength infrared (MWIR) applications. PMMA is a low cost material and is widely used in daily life. We examined its optical properties in the mid-infrared range and found that poly(methyl methacrylate) is a highly promising material for MWIR lenses. Besides, liquid PMMA can be formed and solidified easily. Utilizing these characteristics, we proposed a novel way to fabricate PMMA lenses for MWIR range (wavelength from 3.6 to 5 mu m). The fabrication process is much easier and less expensive compared with traditional machining processes. We have designed a PMMA Fresnel lens, which has f-number of 1.40, diameter of 10 mm and focal length of 14 mm. We also successfully fabricated the PMMA Fresnel lens using the molding process. Both structure and optical analyses show that the PMMA Fresnel lenses could meet the design parameters.

• 出版日期2012-4