Weak and Strong Coupling of Light for Ultrasensitive Detection of Chiral Molecules – PhD (Funded)

Apply by 17th February 2020

Background

Optical micro/nanostructures are important for many applications such as lasers, metrology and biosensing. Optical microcavities confine a light wave into a small and controlled sensing area. Within this sensing area, light matter interactions can be precisely controlled and explored. By adding a metal nanostructure, it becomes possible to explore the interaction of single molecules with the metal nanostructure. Particularly interesting is the study of the interaction of the molecule with a plasmon resonance that is excited in the metal nanostructure. Our goal is to study this fundamental interaction between a single molecule and a plasmon resonance, preferably in the weak and strong coupling regimes. Further, by introducing an intracavity Faraday Effect and external magnetic fields, the interaction of light with the molecule becomes sensitive to the molecule’s handedness (chirality). It is our ambitious goal to exploit weak and strong light-molecule interactions and their dependence on chirality and magnetic fields to detect the handedness of a single molecule.

Your Project

You will work with two optical sensing platforms that are available in our laboratory and that you will modify further to achieve project goals. The first platform utilises a glass microsphere optical cavity that confines light on a whispering gallery mode. You will introduce the Faraday Effect by fabricating the microcavity from magneto-optical glasses, or by coating the cavity with molecules that exhibit a large Faraday rotation. You will learn how to modify this cavity with various plasmonic nanoparticles. You will probe the light matter interactions between plasmonic nanoparticles and single-molecules using non-fluorescent, fluorescent, and chiral molecules. The second platform you will work with confines light on silicon photonic crystal waveguides. You will investigate means for introducing plasmonic nanostructures and Faraday rotation on this platform. You will manipulate both sensing experiments with externally modulated magnetic fields that reach up to 1 Tesla at the sensing region. The two platforms will provide you with an extraordinary parameter space to probe weak, strong and chiral light matter interactions of plasmonic nanoparticles with single molecules.

What we are looking for

We are looking for well-motivated students with a passion in optics, physics, nanophotonics, applied electromagnetic theory, and knowledge of biosensing or enthusiasm for single-molecule biosensing. You are enthusiastic about working in our interdisciplinary research team to develop single-molecule optical sensing methodologies.

Prof Frank Vollmer

University of Exeter, Living Systems Institute

Exeter EX4 4QD, United Kingdom

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