Physics

Dr. Adarsh B Vasista
University of Exeter, United Kingdom

Abstract:

Absorption, emission, and transfer of energy in the form of light in molecular systems depends on the local environment of the molecule, defined by local density of optical states (LDOS). The coupling of molecules to its environment decides the extent to which these properties could be changed. Thus, structuring the environment and coupling is pivotal. Micro-resonators provide enhanced local electric fields and access to a large reservoir of LDOS. By spectrally and spatially matching the molecular absorption and mode profile of the resonator one can achieve strong molecule – resonator coupling resulting in alteration of the energy landscape of the molecule.
Microspheres, often called as soft micro-resonators, are moldable, bio – compatible, and open dielectric cavities. They support spectrally sharp resonances called whispering gallery modes (WGMs). As microspheres can be easily trapped and moved in a microfluidic environment, they are ideal candidates to study the effect of resonators in biological molecules. In addition, WGMs have angular momentum and vector optical polarization which provide anisotropic coupling constants. In this talk I will focus on the importance of light – matter coupling in soft microcavities with specific emphasis on aspects of strong coupling.

References
[1] A B Vasista and W L Barnes, arxiv:1912.01564 (2019)
[2] A B Vasista et.al., Adv. Opt. Mater.,6,1801025 (2018)
[3] A B Vasista et.al., J.Opt. 21,035002 (2019)