Strong Couplings Between Optical Nanocavities And Quantum Emitters

Interactions between light and matter play a crucial role in spectroscopy,sensing,quantum information processing and lasers.Generally speaking,the direct interactions between light and matter are very weak in quantum electrodynamics.Owing to the optical nanocavities with the capability to localize the light energy into a tiny region or localize the light energy for a long time,therefore placing matter into the optical nanocavities has a great significance to realize the strong interactions between light and matter.However,there are still great challenges in achieving strong coupling between a single molecule and an optical nanocavity at room temperature.In this paper,the strong coupling between a single molecule and the optical nanocavity was achieved theoretically,aiming to find a way to achieve such a strong coupling experimentally.1.A new semi-analytic method,aiming to calculate the optical spectral of coupling between the electric/magnetic dipole of arbitrary resonators and molecules or quantum dots,was proposed based on the multipole decomposition method and Mie theory,which can save a large amount of time compared to general simulation methods.We derive the coupling capability parameter,based on which we compared some common resonator cavities and propose a structure with a better coupling capability parameter,a raindrop dimer.The strong coupling between the raindrop dimer and an individual common molecule(3.8)can be achieved under ambient conditions.Finally,an additional peak was found and investigated,which was attributed to the saturation effect of molecules.2.We expanded the conditions for the application of the semi-analytical method.With that,the optical interaction between the higher-order WGM mode of the dielectric sphere and the magnetic ion cluster was investigated,which achieved strong coupling.It was also found that the match of spectra width of the magnetic ion cluster and the WGM is crucial to the interaction between them.Meanwhile,the effect of some factors,such as the refractive index,the size of the dielectric sphere and the transition dipole moment of the magnetic ions,and the intensity of the incident plane wave,on coupling was also investigated.