title: Time-resolved imaging of near-fields in THz antennas and direct quantitative measurement of field enhancements.
abstract: We investigate the interaction between terahertz waves and resonant antennas with sub-cycle temporal and λ/100 spatial resolution. Depositing antennas on a LiNbO₃ waveguide enables non-invasive electro-optic imaging, quantitative field characterization, and direct measurement of field enhancement (up to 40-fold). The spectral response is determined over a bandwidth spanning from DC across multiple resonances, and distinct behavior is observed in the near- and far-field. The scaling of enhancement and resonant frequency with gap size and antenna length agrees well with simulations.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Werley
authors.forename: Kebin
authors.initials: K
authors.lastname: Fan
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Strikwerda
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Teo
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Richard D
authors.initials: RD
authors.lastname: Averitt
authors.forename: Keith A
authors.initials: KA
authors.lastname: Nelson