Interferometric scattering (iSCAT) microscopy enables us to track nm-sized objects with high spatial and temporal resolutions and permits label-free imaging of biomolecules. Its superb sensitivity, however, comes at a cost by several downsides, such as slow three-dimensional imaging and limited vertical tracking. Here, we propose a new method, Remote Focusing-iSCAT (RF-iSCAT) microscopy, to visualize a volume specimen by imaging sections at different depths without translation of either the objective lens or sample stage. We demonstrate the principle of RF-iSCAT by determining the z-position of submicrometer beads by translating the reference mirror instead. RF-iSCAT features an unprecedentedly long range of vertical tracking and permits fast but vibration-free vertical scanning. We anticipate that RF-iSCAT would enhance the utility of iSCAT for dynamics study.
Bibliographical noteFunding Information:
Funding. Institute for Basic Science (IBS-R023-D1); National Research Foundation of Korea (NRF-2018K1 A4A3A01064272, NRF-2019R1H1A2077487).
© 2020 Optical Society of America.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics