▎ 摘　　要

Current research on localized surface plasmon polaritons (LSPPs) and delocalized surface plasmon polaritons (DSPPs) has rarely reported on the interactions between the two phenomena. In this study, we present a light source based on multilayer graphene to control the interactions between LSPP and DSPP in the terahertz (THZ) band. Arrays of graphene ribbons and periodic grating waveguide are used. Then, DSPP and LSPP occur at the array graphene/glass and grating/graphene interfaces, respectively. The characteristic interaction between LSPP and DSPP can be observed on the third layer of graphene. We analyze the characteristic parameters of LSPP-DSPP, including resonance condition, eigenfrequency, and dispersion. We find that a dynamic tuning for LSPP-DSPP coupling can be achieved by controlling the Fermi level and grating parameters. Structural feature analysis shows that the model can induce emergent strong lasing under the condition of subwavelength size. Under the consistent mode between LSPP and DSPP in the THZ band, we can obtain increased coupling strength and enhanced mixed mode. Mode coupling significantly improves DSPP resonance through electric field distribution. Crossing characteristics are discovered in the absorption spectra of different Fermi levels, indicating that the coupling strength of LSPP-DSPP is interconnected. Thus, we can control the mode of LSPP-DSPP by tuning the Fermi level. This structure provides the light source device for SPP to excite the circuit so as to realize a large bandwidth and super-fast data transfer.