Photonic resonator interferometric scattering microscopy

The capability to image the species of interest without exogenous labeling with visible light has been one of the central mission for modern optical microscopy. Among the huge variety of photophysical processes in light-matter interaction, elastic scattering is one of the most universal and fundamental phenomena, and thus is an ideal means for optical contrast generation. Recent development in interferometric scattering microscopy has enabled the detection of individual nanoscopic objects as small as single proteins by their elastically scattered light. To push the limit of the smallest detectable features in interferometric imaging system, in this dissertation, we try to address this challenge from the nanophotonic perspective. Specifically, dielectric photonic crystal slabs are designed and utilized as the imaging substrates to improve the imaging sensitivity. First, the delocalized photonic crystal guided resonance can confine light to generate an elevated optical field for the enhanced excitation of elastic scattering light. Additionally, the photonic band edge effect greatly reduces the transmissivity of the incident field, thus resulting in the suppressed background noise and significantly enhanced signal-to-noise ratios. Finally, the far-field angular distribution of the elastic scattered light can be reshaped by the photonic crystal towards smaller numerical aperture, thus allowing for the efficient signal collection by a non-contacting objective. The nanophotonically enhanced imaging platform, named photonic resonator interferometric scattering microscopy, offers a simple and low-cost solution for label-free biosensing for single SARS-CoV-2 viruses and quantitative mass measurement for individual protein molecules.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Li, Nantao

Contributors dc:contributor

• Cunningham, Brian T
• Gruev, Viktor
• Lu, Yi
• Zhao, Yang

• Label free
• Microscopy
• Biosensor
• Nanophotonics
• Imaging

Statement dc:rights

• Copyright 2022 Nantao Li

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/115748

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F115748