Effects of substrate on cavity plasmon polaritons in monolayer MoS2 embedded in an asymmetric cavity

The coupling between plasmons in two-dimensional materials and photons can be enhanced by a Fabry–Pérot (FP) cavity, leading to the formation of cavity plasmon polaritons (CPPs). In this work, we theoretically investigate the effects of substrate on CPPs in monolayer (ML) molybdenum disulfide ( M o S 2 ) embedded in an asymmetric FP cavity. The optical conductivity of ML M o S 2 used here is described by the Drude–Smith model, in which the substrate-induced electronic localization effect is considered. This effect has been experimentally demonstrated for chemical vapor deposition grown M o S 2 in our recent work. Herein, the investigation shows the existence of three types of CPPs in this asymmetric plasmonic system. Meanwhile, we also demonstrate that the substrate can affect the properties of these modes through different mechanisms. These results not only can give us insight into the effects of substrate on plasmon polaritons but also remind us that the differences between the realistic optical parameters of M o S 2 and the ideal ones cannot be neglected in many situations. Moreover, we hope this study can push forward the design and optimization of plasmonic devices based on M o S 2 , such as sensors, attenuators, and detectors.