Research student, Ysgol y Biowyddorau
A detailed understanding of the optical properties of objects with nanometric size is pivotal for describing natural phenomena such as the colour of some minerals and glasses, as well as to design a wide range of photonic devices. In particular, colloidal particles and fabricated nanostructures made of metals such as gold or silver display a rich phenomenology, depending on their shape, size, composition, and surrounding environment.
My PhD project aims at developing and refining linear and nonlinear optical microscopy techniques for nano-object characterization. In particular, we have devised a simple experimental technique capable of measuring quantitatively the absorption and scattering spectra of a single nano-object, which together fully describe the interaction between the particle and the radiation. Quantitative automated analysis of conventional wide-field images provides a high-throughput and high-sensitivity implementation of this approach.
We have relied on numerical modelling (COMSOL software) in order to benchmark the accuracy of our experimental measurements. Indeed, by comparing results of simulation and experiment we are able to infer the size of objects of known shapes, thus limiting the need of costly electron microscopy characterization. However, reproducing the actual illumination and collection properties of a microscope requires sophisticated modelling approaches beyond standard practise. My research has been funded by the European Commission via a Marie Skłodowska-Curie action under an ITN scheme.