Plasmon-exciton coupling in a dimer cavity revisited: effect of excitonic dipole orientation

We revisit plasmon-exciton coupling of a single emitter in a dimer cavity, featuring the analysis of how the excitonic dipole orientation influences the coupling behaviour from both the spectral and temporal aspects. Results demonstrate that the dipolar mode could be suppressed to vanish while the magnitude of the pseudomode could only be suppressed to half of the maximum value. The temporal analysis gives further evidence of this effect on the dipolar mode and pseudomode. The analysis might have potential significance on the experimental community as the excitonic dipole orientation could be precisely measured and has a rather important impact on the experiments.