| Popis: |
Optical coupling plays a pivotal role in nanophotonic systems, which can be divided into weak, intermediate, and strong coupling regimes. Determining coupling strength is, therefore, the key to understanding light-matter interactions. State-of-the-art approaches based on spectral-based measurements suffer from relatively large background noise or long accumulation time at single-cavity level, without being able to perform high-throughput characterizations. Here, we report an efficient far-field optical imaging technique that can directly reveal coupling strength in a plasmon-exciton systems, allowing multiple nanocavity emissions to be detected, imaged, and quantified individually. A light harvesting biomolecule- chlorophyll a was employed to study dynamic light-matter interactions in strongly-coupled bio-plasmonic nanocavities. Identification of coupling strength was achieved by extracting RGB values from dark-field images and enhancement factor from fluorescence images. Lastly, we demonstrate the ability to quantify excitons and subtle changes of week coupling interactions in the bioplasmonic nanocavity. Our findings may deepen our understanding of fundamental science of light-matter interactions, paving new avenues toward real-world applications in quantum-based biosensing and imaging. |
