Spectral splitting phenomenon caused by strong coupling of surface plasmon polariton mode and epsilon-near-zero mode

Abstract The strong coupling effect plays an important role in optimizing the optical properties of nano-photonics and improves the efficiency of manipulating light. However, the coupling systems for nano-photonic devices usually have the problems of complex structure, large size and low coupling strength. To address these issues, we design a nanograting structure to realize the strong coupling of the surface plasmon polariton (SPP) mode and the epsilon-near-zero (ENZ) mode. The reflection spectra of the designed nanostructure show obvious Rabi splitting phenomenon. The Rabi splitting phenomenon is further verified by the theoretical result. In addition, the factors influenced the coupling effect strength in the nanostructure are analyzed. The proposed nanostructure can be used in nano-photonic devices such as sensors.