Analysis of the extraordinary transmission properties of arrays of subwavelength holes on a metal film in the terahertz region

The extraordinary transmission properties of terahertz waves through arrays of subwavelength holes on a metal film have been investigated. The effects of the geometrical parameters and dielectrics filling the hole on transmission properties have been explored. The results show that the resonance peak shifts to long wavelength as the hole width and lattice period constant increase. As the refractive index of the dielectric materials filling the hole increases, the transmittance increases and the resonance peak wavelength changes to low frequency. The phase retardation can be flexibly changed by varying the geometrical parameters and dielectric materials filling in the hole.