Webinar on June 2, 2021, 3:45 pm UTC+2

Quantitative Absorption Imaging by Widefield Interferometric Photothermal Microscopy

Photothermal microscopy is a highly sensitive technique to probe local heat generated by single nano-objects through light absorption. Accurate quantification of the absorption from the photothermal signal, however, is nontrivial due to the interferometric nature of photothermal detection. By adding a heating beam to a widefield interferometric scattering (iSCAT) microscopy, we demonstrate simultaneous photothermal and scattering imaging. The important role of the sample scattering in the photothermal measurement will be discussed. This finding paves the way to accurate and sensitive absorption-based imaging in complex biological samples where the scattering is often spatially heterogeneous.