Point spread function engineering for spiral phase interferometric scattering microscopy enables robust 3D single-particle tracking
arXiv:2402.13652 · doi:10.1021/acsphotonics.4c01481
Abstract
Interferometric scattering (iSCAT) microscopy is currently among the most powerful techniques available for achieving high-sensitivity single-particle localization. This capability is realized through homodyne detection, where interference with a reference wave offers the promise of exceptionally precise three-dimensional (3D) localization. However, the practical application of iSCAT to 3D tracking has to date been hampered by rapid oscillations in the signal-to-noise ratio (SNR) as particles move along the axial direction. In this study, we introduce a novel strategy based on back pupil plane engineering, wherein we use a spiral phase mask to re-distribute the phase of the scattered field of the particle uniformly across phase space, thus ensuring consistent SNR as the particle moves throughout the focal volume. Our findings demonstrate that this modified spiral phase iSCAT exhibits greatly enhanced localizability characteristics. We substantiate our theoretical results with numerical and experimental demonstrations, showcasing the practical application of this approach for high-precision, ultrahigh-speed (20,000 frames per second) 3D tracking, and characterization of freely diffusing nanoparticles.
21 pages, 5 figures
References in corpus (4)
- Characterizing and tracking single colloidal particles with video holographic microscopy
- Fundamental bounds on the precision of iSCAT, COBRI and dark-field microscopy for 3D localization and mass photometry
- Optical Fingerprint of Flat Substrate Surface and Marker-free Lateral Displacement Detection with Angstrom-level Precision
- Precise characterization of nanometer-scale systems using interferometric scattering microscopy and Bayesian analysis