Zhu Xufeng, Fang Wei, Lei Jian, Li Zhangyin, Xie Fei, Cao Yaoyu, Zhang Yaping, Qin Fei, Li Xiangping
Opt Lett. 2020 Apr 1;45(7):1798-1801. doi: 10.1364/OL.389702.
Microlens arrays (MLAs) are widely used in optical imaging, dense wavelength division multiplexing, optical switching, and microstructure patterning, etc. However, the light modulation capability for both the conventional refractive-type MLA and planar diffractive-type MLA is still staying at the diffraction-limited scale. Here we propose and experimentally demonstrate a high numerical aperture (NA) supercritical lens (SCL) array which could achieve a sub-diffraction-limited focal spot lattice in the far field. The intensity distribution for all the focal spots has good uniformity with the lateral size around ${0.45}\lambda {\rm /NA}$0.45λ/NA (0.75X Airy unit). The elementary unit in the SCL array composes a series of concentric belts with a feature size in micrometer scale. By utilizing an ultrafast ultraviolet lithography technique, a centimeter scale SCL array could be successfully patterned within 10 mins. Our results may provide possibilities for the applications in optical nanofabrication, super-resolution imaging, and ultrafine optical manipulation.
微透镜阵列（MLA）广泛应用于光学成像、密集波分复用、光开关和微结构图案化等领域。然而，传统折射型MLA和平面衍射型MLA的光调制能力仍停留在衍射极限尺度。在此，我们提出并通过实验证明了一种高数值孔径（NA）超临界透镜（SCL）阵列，它能够在远场实现亚衍射极限焦斑晶格。所有焦斑的强度分布具有良好的均匀性，横向尺寸约为${0.45}\lambda {\rm /NA}$（0.75倍艾里单位）。SCL阵列中的基本单元由一系列特征尺寸为微米级的同心带组成。通过利用超快紫外光刻技术，可在10分钟内成功制备出厘米级的SCL阵列。我们的结果可能为光学纳米制造、超分辨率成像和超精细光学操纵等应用提供可能性。
