Resonant transmission through periodic subwavelength terahertz metallic slits based on a quartz plate

This article proposes the resonant transmission characteristic through the periodic subwavelength metal-insulator-metal (MIM) waveguide on a quartz plate at terahertz frequencies. By applying the multiregion problem to the mode matching technique (MMT), the total reflection and transmission characteristics of the periodic MIM waveguide can be resolved as functions of the thickness of the MIM waveguide, the gap width of the MIM waveguide, the thickness of the quartz plate, and frequency. To validate the results of the proposed MMT, the transmission results are compared with the results using a commercial electromagnetic simulation software (XFdtd). The similar results demonstrate that the proposed MMT is proper to compute the reflection and transmission characteristics of the periodic MIM waveguide on the real quartz plate and providing in-depth intuition for resonant transmissions using the modal approach.