A plasmonic colour filter based on metal-insulator-metal square micro-ring cavities for visible spectrum

Abstract

In this paper, we presented a metal-insulator-metal (MIM) waveguide resonator design for filtering white light into individual colours. Six square micro-ring cavities of different sizes are side coupled to MIM bus waveguide. By careful selection of cavity size and distance between bus waveguide and micro-ring cavities, the resonator can selectively couple to intensity maxima of different photonic modes and, as a result, preferentially select any of the primary colours. The spectral characteristics of the resonator are studied by varying the geometric parameters using the finite element method (FEM).