Super-Resolution Imaging with Patchy Microspheres

Shang, Qingqing [Key Laboratory for Opto-Electronic Technology of Jiangsu Province, Nanjing Normal University, Nanjing 210023, China] Tang, Fen [School of Computer and Electronic Information, Nanjing Normal University, Nanjing 210023, China] Yu, Lingya [School of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 1UT, UK] Oubaha, Hamid [UCL] Caina Aysabucha, Darwin Rodolfo [UCL] Yang, Songlin [Advanced Photonics Center, Southeast University, Nanjing 210096, China] Melinte, Sorin [UCL] Zuo, Chao [Smart Computational Imaging Laboratory (SCILab), School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China] Wang, Zengbo [School of Computer Science and Electronic Engineering, Bangor University, Bangor LL57 1UT, UK] Ye, Ran [School of Computer and Electronic Information, Nanjing Normal University, Nanjing 210023, China] et al.[show all]

The diffraction limit is a fundamental barrier in optical microscopy, which restricts the smallest resolvable feature size of a microscopic system. Microsphere-based microscopy has proven to be a promising tool for challenging the diffraction limit. Nevertheless, the microspheres have a low imaging contrast in air, which hinders the application of this technique. In this work, we demonstrate that this challenge can be effectively overcome by using partially Ag-plated microspheres. The deposited Ag film acts as an aperture stop that blocks a portion of the incident beam, forming a photonic hook and an oblique near-field illumination. Such a photonic hook significantly enhanced the imaging contrast of the system, as experimentally verified by imaging the Blu-ray disc surface and colloidal particle arrays.