Tuning the dispersion of effective surface plasmon polaritons with multilayer systems

Abstract

Recently, effective surface plasmon polaritons (ESPPs) induced by structural dispersion in bounded waveguides were theoretically demonstrated and experimentally verified. Despite the theoretical and experimental efforts, whether ESPPs can mimic real SPPs in every aspect still remains an open question. In this work, we go one step further to study the hybridization of ESPPs in multilayer systems. We consider transverse electric (TE) modes in a conventional rectangular waveguide and a parallel-plate waveguide (PPW) and derive analytically the dispersion relations and asymptotic frequencies of the corresponding ESPPs modes in sandwiched structures consisting of alternating dielectrics of different permittivities. Our results show that the ESPPs can be categorized into odd and even parities (owing to the 'plasmon' hybridization) in a similar way as natural SPPs supported by the insulator/metal/insulator (IMI) and metal/insulator/metal (MIM) heterostructures in the optical regime. The similarities and differences between ESSPs and their optical counterparts are also discussed in details, which may provide valuable guidance for future application of ESPPs at the microwave and terahertz frequencies.

Microwave Surface Plasmon Polariton-Like Sensor Based on Half-Mode Substrate Integrated Waveguide for Highly Sensitive Dielectric Constant Detection

“…In other words, if two HM SIWs with the same width and different dielectric materials are coupled, in certain frequency range the real parts of the effective dielectric constants of the two would have opposite signs, which would open up a possibility for SPP propagation. This concept, however in parallel-plate waveguide, has been demonstrated in [36,37] and exploited as filter in [38,39] and in multilayer waveguide system [40]. Here, for the first time it is shown how the SPP-like propagation can be achieved in HM SIW and used for sensing applications in microwave regime.…”

“…In the case that the two parts are filled with different materials, there is a frequency range in which one part exhibits positive real part of the effective permittivity and the other negative real part of the effective permittivity, allowing for SPP to occur at the I interface. This concept has been applied only in the passive filter [38,39] and multilayer waveguide systems [40], and has never been used for sensing purposes in spite of being very promising for highly sensitive and accurate detection in microwave regime.…”

Integrated spoof plasmonic circuits

“…However, this method cannot be used to describe the case that the strip is integrated with the dielectric substrate, which is commonly used in real applications. In order to solve this problem, the effective circuit model is introduced to describe the EM behavior of the spoof SPPs from the circuit view [26,[38][39][40][41]. In Refs.…”

Mimicking Localized Surface Plasmons with Structural Dispersion

“…Alternatively, it has been shown that low‐frequency plasmonics can also be realized with structured dispersion in bounded waveguides . Recently, in a couple of scenarios, this approach has been successfully applied to mimic propagating SPPs exhibiting spatial decay on both sides of the interface.…”