Broadband Electromagnetic Waves Harvesting Based on Effective Surface Plasmon Polaritons

In this paper, a novel structure is proposed for broadband electromagnetic energy harvesting based on effective surface plasmon polaritons (ESPPs) under the framework of conformal transformation optics(TO). By inserting a dielectric cylindrical structure with crescent-shaped cross-section into a dielectric-filled rectangular waveguide, the transverse-electric (TE) mode in the waveguide is smoothly transformed into ESPPs at the bottom of the crescent and propagate towards the singularity of the crescent with decreasing velocity down to zero. The ESPPs energy is harvested all the way towards the singularity due to the interaction between compressed ESPPs and the surrounding lossy dielectrics and metallic wires. Simulation results show that broadband transformation and energy harvesting of ESPPs with efficiency about 25% can be achieved in this scheme. This work paves the way for broadband EM energy harvesting at microwave and terahertz frequencies.