Band-pass property of a three-dimensional slit-type plasmonic filter

摘要

A band-pass property of a three-dimensional (3D) slit-type plasmonic filter based on a metal-insulator-metal waveguide is investigated using the frequency-dependent FDTD method. It is revealed that the 3D filter with a typical metal thickness of 0.05 μm results in a broad transmission bandwidth of 94%, while a two-dimensional filter shows a narrow one of 2%. To obtain a narrow transmission bandwidth for the practical 3D filter, we insert a dielectric material into the slit section and increase the metal thickness to 0.2 μm. It is found that the bandwidth is significantly reduced to 9% for the 3D filter.