Coupling between surface plasmons and Fabry-Pérot modes in metallic double meander structures

Abstract

The excitation and transfer of evanescent electromagnetic waves appears as key challenge for the realization of optical imaging devices with super resolution. In this process surface plasmon polaritons (SPP) overtake the role as indispensable mediators between source fields and propagating fields. Therefore, the interaction between SPPs and the vacuum field in a double meander structure (DMS) is investigated. The occurrence of Fabry-Perot (FP) modes within such a cavity and the SPP modes of the meander structure is analyzed to understand the interaction of both mode systems in the combined double meander structure. We show that the known Fano-type passband of single meander structures keeps its dominant role in the DMS and demonstrate the frequency selective role of meander mirrors within this meander cavity. The meander geometry determined passband frequency position also controls nearly solely the passband of the DMS. For far field superlenses (FSL) the energy transfer at low loss over practically arbitrary distances inside the structure is a key property. A resonant amplitude transfer can be obtained between resonantly coupled meander surfaces for unlimited distances in practical cases. This property enables a controlled transformation of evanescent modes to traveling wave modes of higher diffraction order useful for superlens operation.