Vectorial Fluorescence Emission from Microsphere Coupled to Gold Mirror

TL;DR

This study investigates the fluorescence emission from a microsphere coupled to a gold mirror, analyzing the momentum space distribution and polarization dependence to explore potential applications in nano-optics and meta-surfaces.

Contribution

It introduces a detailed analysis of fluorescence emission mediated by whispering gallery modes in microspheres on gold mirrors, revealing polarization and wavevector dependencies.

Findings

Intensity dependence of split cavity modes on in-plane wavevector

Polarization-dependent far-field emission distribution

Sphere-image sphere model explains exotic emission patterns

Abstract

We report on the generation, and momentum space distribution of fluorescence emission from individual SiO2 microsphere on dye coated Au mirror. The molecular fluorescence emission mediated via whispering gallery modes of the sphere is studied using polarization resolved optical energy-momentum micro-spectroscopy. Our experiments reveal intensity dependence of split modes of the cavity as a function of in-plane wavevector and emission polarization in the far field. The exotic far-field distribution can be understood by sphere-image sphere model that further reveals the polarization dependence of the split modes. The presented results reveal the potential of metallo-dielectric soft micro-cavities to engineer molecular emission that can encode spin and orbital angular momentum states and can be further extrapolated to realize dye-loaded active meta-atoms and meta-surfaces.