Related Experiment Video
Updated: Feb 2, 2026

Isolation and Fluorescence Imaging for Single-particle Reconstruction of Chlamydomonas Centrioles
Published on: September 21, 2018
Single-particle photothermal imaging via inverted excitation through high-Q all-glass toroidal microresonators
Abstract:
Whispering-gallery mode (WGM) microresonators have recently been employed as platforms for label-free single-molecule and single-particle detection, imaging, and spectroscopy. However, innovations in device geometry and integration are needed to make WGM microresonators more versatile for biological and chemical applications. Particularly, thick device substrates, originating from wafer-scale fabrication processing, prevent convenient optical interrogation. In this work, we fabricate all-glass toroidal microresonators on a coverslip thickness (~170 μm) substrate, enabling excitation delivery through the sample, simplifying optical integration. Further, we demonstrate the application of this new geometry for single-particle photothermal imaging. Finally, we discover and develop simulations to explain a non-trivial astigmatism in the point spread function (PSF) arising from the curvature of the resonator.
Related Concept Videos
Toroids
When connected to a supply, the magnetic field generated in the toroid has field lines circular and concentric to its axis. Conventionally, the direction of this magnetic field is expressed using the right-hand rule. If the fingers of the right hand curl in the current direction, the thumb points in...
Inverting and Non-inverting OpAmps
Angular Momentum: Single Particle
The Looking Glass Self
Principle of Linear Impulse and Momentum for a Single Particle
Delving...
Electron Microscope Tomography and Single-particle Reconstruction
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...

