Analysis of Filter and Waveguide Effect Based on the MIM Nanodisk with a Metallic Block

Abstract

A novel and meaningful plasmonic filter based on the metal‐insulator‐metal (MIM) waveguides directly connected to a nanocavity with a metallic block is proposed and demonstrated numerically. By the effective index method and the resonant theory of disk‐shaped nanocavity, we reveal that the resonant wavelengths can be simply tuned by adjusting the height of the block, which is in accordance with the results calculated by finite‐difference time‐domain (FDTD) simulations. We also rotate the metallic block to achieve two resonant modes. One mode shows a blue shift, and the other mode shows a red shift. It is shown that the proposed structure performs as a bend waveguide not a filter when the width of the block increases to hundreds of nanometers. The proposed structure will have significant potential applications in nanointegrated circuits for optical filtering and processing.