A multi-layer structure consisting of metal and dielectric layers which allows coupling between surface plasmon polaritons and waveguide modes is studied by calculating reflectivity curves of incident light. A wide waveguide structure is employed to ensure SPP resonance with different order waveguide modes when varying coupling layer thicknesses. Multi-hybrid plasmonic waveguide modes (HPWG) are formed in the coupled system. The weight fractions of metal SPP deduced from losses of HPWG modes are calculated for each hybridized mode, which can be considered as a parameter of evaluating coupling strength. Three different evolution stages for hybrid modes are clearly distinguished based on the variation of loss with spacer layer thickness. The interaction between SPP and waveguide experiences a series of change from weak Fano resonance, via strong coupling, finally to weak coupling process. In case of strong coupling regime, the contribution of metal SPP for low order hybrid modes starts to increase and then decreases with decreasing spacer layer thicknesses. Furthermore, difference of resonant behavior for hybrid modes in both weak coupling stages is analyzed in detail.

通过计算入射光的反射率曲线，研究了由金属和介电层组成的多层结构，该结构允许表面等离激元极化子和波导模式之间的耦合。当改变耦合层厚度时，采用宽波导结构以确保在不同阶波导模式下的SPP谐振。在耦合系统中形成了多混合等离子体激元波导模式（HPWG）。由HPWG模式的损失推导出的金属SPP的重量分数是针对每种混合模式计算的，可以将其视为评估耦合强度的参数。基于损耗随间隔层厚度的变化，可以清楚地区分混合模式的三个不同演变阶段。SPP和波导之间的相互作用经历了弱Fano共振的一系列变化，通过强耦合，最后到弱耦合过程。在强耦合机制的情况下，金属SPP对低阶混合模式的贡献开始增加，然后随着间隔层厚度的减小而减小。此外，详细分析了两个弱耦合阶段中混合模式的共振行为差异。