High-Q and Intense Lattice Plasmon Resonance in Hexagonal Nonclose Packed Thin Silver Nanoshells Array

We theoretically demonstrate a high-Q and intense lattice plasmon resonance supported by the hexagonal nonclose packed thin silver nanoshells array. By introducing the diffraction coupling mechanism, the high-Q and intense lattice plasmon mode stemmed from the coupling between the TM1 cavity plasmon mode and the diffraction mode of the first-order Wood anomaly is obtained in the thin silver nanoshells array, successfully solving the trade-off between the Q-factor and the resonance intensity of the cavity plasmon mode existed in a single silver nanoshell. In particular, a maximum Q-factor up to 610 of the lattice plasmon resonance is successfully achieved at 870 nm in the silver nanoshell array with an optimal silver thickness of 20 nm.