Photothermal Microscopy and
Spectroscopy Webinar

Photothermal microscopy is a versatile tool for imaging nano-objects. However, understanding the spatial resolution that can be achieved is a complex problem, as there are contributions from the properties of the pump and probe lasers and the optics used in the experiments, as well as from the length scale for heat diffusion in the environment. In this talk I will discuss recent work on investigating the effect of modulation frequency on the spatial resolution for different types of samples: small metal nanoparticles [1] and micron sized polymer beads. These two systems show different effects, and in some situations the size of the features in the photothermal images can exceed the physical size of the objects being imaged. Experiments where an incoherent LED lights source is used as a probe will also be presented.

1. B. S. Brown, G. V. Hartland, J. Phys. Chem. C 126, 3560–3568 (2022).