Far-field transient absorption nanoscopy with sub-50 nm optical super-resolution

Authors

• Yali Bi, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology
• Chi Yang, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and Technology
• Lei Tong, Huazhong University of Science and Technology
• Haozheng Li, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and Technology
• Boyu Yu, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and Technology
• Shuai Yan, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and Technology
• Guang Yang, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and Technology
• Meng Deng, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology
• Yi Wang, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology
• Wei Bao, University of Nebraska-LincolnFollow
• Lei Ye, Huazhong University of Science and TechnologyFollow
• Ping Wang, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology & Huazhong University of Science and TechnologyFollow

ORCID IDs

https://orcid.org/0000-0003-2974-2625

Document Type

Article

Date of this Version

2020

Citation

Vol. 7, No. 10 / October 2020 / Optica 1402-1407

https://doi.org/10.1364/OPTICA.402009

Comments

2020 Optical Society of America

Abstract

Nanoscopic imaging or characterizing is the mainstay of the development of advanced materials. Despite great progress in electronic and atomic force microscopies, label-free and far-field characterization of materials with deep sub- wavelength spatial resolution has long been highly desired. Herein, we demonstrate far-field super-resolution transient absorption (TA) imaging of two-dimensional material with a spatial resolution of sub-50 nm. By introducing a donut- shaped blue saturation laser, we effectively suppress the TA transition driven by near-infrared (NIR) pump–probe photons, and push the NIR-TA microscopy to sub-diffraction-limited resolution. Specifically, we demonstrate that our method can image the individual nano-grains in graphene with lateral resolution down to 36 nm. Further, we perform super-resolution TA imaging of nano-wrinkles in monolayer graphene, and the measured results are very consistent with the characterization by an atomic force microscope. This direct far-field optical nanoscopy holds great promise to achieve sub-20 nm spatial resolution and a few tens of femtoseconds temporal resolution upon further improvement and represents a paradigm shift in a broad range of hard and soft nanomaterial characterization.