Pseudo-optical fluid of continuous power flow from plasmonic coupling

Abstract A significant challenge for plasmonics as an enabling technology for energy harvesting and conversion processing is the active control of light on the nanoscale. By exploiting the resonant absorption spectra of silver nanoparticle dimer array, the theoretical results show that the resonant transverse mode and longitudinal mode is defined by the direction of dipole moment. Both of this two kind of plasmonic coupling mode induces continuous power flow around the nanoparticle, namely an analogy of pseudo-optical fluid. The direction of the circulating optical energy is governed by the spatial phase reversal of the Poynting vector. Based on the hydrodynamic theory, the negative pressure of photon is proposed to describe the intensely accumulated energy within a nanoscale volume, and the significant energy density satisfies the forming condition of pseudo-optical fluid. The analytical assumptions build the bridge for the electrodynamics and hydrodynamics to achieve dynamically-tunable and switchable vortex-operated plasmonic nanodevice for subwavelength waveguides, high-energy batteries and laser light sources.