Photonic Systems Laboratory, Holonyak Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
Nat Commun. 2020 Jun 2;11(1):2754. doi: 10.1038/s41467-020-16610-0.
Why can we not see nanoscale objects under a light microscope? The textbook answers are that their relative signals are weak and their separation is smaller than Abbe's resolution limit. Thus, significant effort has gone into developing ultraviolet imaging, oil and solid immersion objectives, nonlinear methods, fluorescence dyes, evanescent wave tailoring, and point-spread function engineering. In this work, we introduce a new optical sensing framework based on the concepts of electromagnetic canyons and non-resonance amplification, to directly view on a widefield microscope λ/31-scale (25-nm radius) objects in the near-field region of nanowire-based sensors across a 726-μm × 582-μm field of view. Our work provides a simple but highly efficient framework that can transform conventional diffraction-limited optical microscopes for nanoscale visualization. Given the ubiquity of microscopy and importance of visualizing viruses, molecules, nanoparticles, semiconductor defects, and other nanoscale objects, we believe our proposed framework will impact many science and engineering fields.
为什么我们不能在光学显微镜下看到纳米级物体？教科书上的答案是，它们的相对信号较弱，且它们的分离小于阿贝分辨率极限。因此，人们投入了大量精力来开发紫外线成像、油浸和固体浸没物镜、非线性方法、荧光染料、消逝波修饰和点扩散函数工程。在这项工作中，我们引入了一种新的基于电磁峡谷和非共振放大概念的光学传感框架，以在纳米线传感器的近场区域直接观察宽视场显微镜 λ/31 尺度（25nm 半径）的物体，视场为 726μm×582μm。我们的工作提供了一个简单但高效的框架，可以将传统的受衍射限制的光学显微镜转换为纳米级可视化。鉴于显微镜的普遍性以及可视化病毒、分子、纳米粒子、半导体缺陷和其他纳米级物体的重要性，我们相信我们提出的框架将影响许多科学和工程领域。
