Deng Chun, Kim Hyeongwon, Ki Hyungson
Opt Express. 2019 Sep 30;27(20):28679-28691. doi: 10.1364/OE.27.028679.
We present the design, fabrication, and characterization of a compound infrared microlens array having an ultrashort focal length and a hyperbolic profile that comprises a PDMS microlens array and a GRIN lens. A concave microlens mold was first fabricated on a fused silica substrate using femtosecond laser irradiation followed by a wet etching process, and a standard replication process was employed to fabricate a PDMS convex lens array. To shorten the focal length further and cut off the visible spectrum of light, a graded DLC/silicon coating, which functioned as a GRIN lens and a visible light cut-off filter, was additionally deposited using dual-beam pulsed laser deposition. The lenslet diameter was 6 µm and the graded coating reduced the focal length from 4.5 to 2.9 µm.
我们展示了一种具有超短焦距和双曲线轮廓的复合红外微透镜阵列的设计、制造和特性，该阵列由一个聚二甲基硅氧烷（PDMS）微透镜阵列和一个梯度折射率（GRIN）透镜组成。首先，使用飞秒激光辐照在熔融石英衬底上制造一个凹面微透镜模具，随后进行湿法蚀刻工艺，然后采用标准复制工艺制造一个PDMS凸透镜阵列。为了进一步缩短焦距并截止光的可见光谱，使用双光束脉冲激光沉积额外沉积了一种渐变的类金刚石碳（DLC）/硅涂层，该涂层起到GRIN透镜和可见光截止滤光片的作用。微透镜直径为6 µm，渐变涂层将焦距从4.5 µm减小到2.9 µm。
