Diffraction-limited microfocusing generated by polymer microlines separated by 1.12 μm
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 3D wide-field transmission microscopy. A line pair, having a width W = 0.4 µm and a height H = 0.8 µm, leads to a 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 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.
作者单位：Université des Sciences et de la Technologie Houari Boumediene
Université des Sciences et de la Technologie Houari Boumediene
Ecole normale superieure de Lyon
tellal azeddine,ziane omar,Baldeck Patrice. Diffraction-limited microfocusing generated by polymer microlines separated by 1.12 μm[J].Chinese Optics Letters,2019,17(8):08.