The effects of silver slabs in nanodisk resonator of plasmonic tunable band-pass filter

A novel and simple method to meliorate nanodisk resonator using silver slabs is proposed. In this regard, we numerically and theoretically compared the meliorated resonator with the nanodisk resonator without silver slabs at the plasmonic tunable band-pass filter. It was found that configuration of the proposed resonator leads to reduction of the plasmonic filter dimensions. Also, we calculated the amount of this reduction based on the disk-shaped nanocavity resonant theory and the meliorated resonator simulation results. Therefore, the resonance wavelengths depend on the relative permittivity and nanocavity radius which were consistent with the outcomes achieved by the simulations of FDTD (Finite-Difference Time-Domain). The FDTD simulations shown transmission spectra were tunable by changing of structure parameters. Through this method, it was revealed that simple plasmonic devices can be designed with smaller dimension for highly integrated optical devices.