Terahertz Transparent Electrode Using Tripod Metal Aperture Array

In this paper, a high transmission terahertz (THz), polarization insensitive electrode was designed and fabricated to modulate a liquid crystal electro-optic device in the THz regime. The designed electrode consists of a subwavelength periodic tripod aperture array structure patterned in a gold film deposited on a transparent dielectric substrate. The maximum feature size of the structure is maintained below a fraction of the thickness of the electro-optic device to allow a fringing field to uniformly excite the entire electrode area. The transmission reaches as high as 93% in measurements.