Diffraction-limited microfocusing generated by polymer microlines separated by 1.12μm

• 来源期刊: 中国光学快报（英文版）
• 年，卷（期）: 2019,（8）
• 页码范围: 81-86
• 页数: 6页
• 语种: 英文
• DOI: 10.3788/COL201917.082201

摘要

The diffraction of a dielectric microline pair is optimized by numerical simulations to generate an efficient focusing pattern with a micron-scale footprint.Microlines separated by 1.12 μm are fabricated by two-photon polymerization on a glass substrate,and their diffraction pattern is characterized by three-dimensional wide-field transmission microscopy.A line pair,having a width W =0.40 μm and a height H =0.80 μm,leads to diffraction-limited focusing in the visible spectrum.Depending on wavelength,its focal length,lateral resolution,and depth of focus are in the ranges of 0.8-1.3 μm,0.22-0.44 μm,and 1.7-2.13 μm,respectively.Such a microlens based on the diffraction of only two subwavelength scatterers could be used for the design of miniature optical sensors with micron and sub-micron pixels.