Study of dipole arrays at terahertz frequencies

Terahertz subwavelength dipole array designed and fabricated by us could display characteristic resonance in transmission spectra, which also shows resonance redshift with increase in the dipole length. We use this property to realize double-bands filter by fabricating double-dipoles structure. Additionally it is theoretically and experimentally demonstrated that polarization state of terahertz pulse changes with the rotation of sample at specific frequency. This phenomenon originates from dipole resonance, showing that dipole reflects one terahertz-electric-field component along dipole direction while the other perpendicular component transmits dipole without loss. The transmission spectra of our fabricated split-“L” structures further verify our conclusion.