Presentation title:

Optical Microsphere Nanoscope Working in Non-Contact Mode

Department of Electrical and Computer Engineering, National University of Singapore,

4 Engineering Drive 3, Singapore 117576

E-mail address: elehmh@nus.edu.sg

Abstract:

To push the imaging capability of an optical microscope beyond 100 nm is revolutionary in the field of nano-imaging. When a dielectric transparent microsphere at a diameter of a few to dozens of microns is located between the sample surface and objective lens, it was found that this microsphere can image tiny feature sizes down to 50 nm, even 25 nm by coupling it into a confocal microscope. In this talk, both contact and non-contact mode nano-imaging schemes by optical microsphere nanoscope are presented. For the contact mode nano-imaging, a microsphere is in direct touch with sample surfaces, fine features at sub-50 nm can be observed clearly. However, such contact mode operation has a critical drawback: the relative location of the microsphere and sample is fixed and cannot be adjusted freely, thus limiting the imaging field and also contaminating sample surfaces. To address this issue, a non-contact nano-imaging mode for the optical microsphere nanoscope is successfully developed via the precise control of sample movement by nano-stages. The gap between the sample and microsphere is a few microns. As shown in Fig. 1, the features with the size of 77 nm can be observed clearly via the non-contact nano-imaging mode operation. Our recent research progresses on engineered microsphere imaging and compound microsphere lenses imaging will be updated as well. The commercialization progress to push OptoNano 200 (in the process to OptoNano 100) products into the market will also be reported.

Optical microsphere nanoscope to image a magnetic head slide to clearly show 77 nm gap.

Brief Bio: 

Prof. Hong Minghui specializes in laser microprocessing & nanofabrication, optical engineering and laser applications. He has co-authored 15 book chapters, 42 patents granted, ~ 500 scientific papers, and ~ 100 plenary/keynote/invited talks in international conferences. He is a member of organizing committees for Laser Precision Micromachining International Conference (2001~2021), International Symposium of Functional Materials (2005, 2007 and 2014), Chair of International Workshop of Plasmonics and Applications in Nanotechnologies (2006), Chair of Conference on Laser Ablation (2009) and Chair of Asia-Pacific Near-field Optics Conference (2013 and 2019). Prof. Hong is invited to serve as an Editor of Light: Science and Applications, Engineering, Science China G, Physics, Laser Micro/nanoengineering, and Executive Editor-in-chief of Opto-Electronic Advances. Prof. Hong is Fellow of Academy of Engineering, Singapore (FSEng), Fellow of Optical Society of America (OSA), Fellow of International Society for Optics and Photonics (SPIE), Fellow of International Academy of Photonics and Laser Engineering (IAPLE) and Fellow of Institution of Engineers, Singapore (IES). Prof. Hong is currently a Full Professor and the Director of Advanced Research and Technology Innovation Centre, Director of Optical Science and Engineering Centre, Department of Electrical and Computer Engineering, National University of Singapore. He is also a founder of Phaos Technology Pte. Ltd.