Photonic resonator interferometric scattering microscopy

Li, Nantao

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

Description

Title

Photonic resonator interferometric scattering microscopy

Author(s)

Li, Nantao

Issue Date

2022-04-22

Director of Research (if dissertation) or Advisor (if thesis)

Cunningham, Brian T

Doctoral Committee Chair(s)

Cunningham, Brian T

Committee Member(s)

• Gruev, Viktor
• Lu, Yi
• Zhao, Yang

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Label free
• Microscopy
• Biosensor
• Nanophotonics
• Imaging

Abstract

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.

Graduation Semester

2022-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Nantao Li

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