Abstract-Terahertz electro-optic detection using a ⟨012⟩-cut chalcopyrite ZnGeP2 crystal

B. N. Carnio1,a), S. R. Greig1, C. J. Firby1, K. T. Zawilski2, P. G. Schunemann2 and A. Y. Elezzabi


http://scitation.aip.org/content/aip/journal/apl/108/26/10.1063/1.4955040


The electro-optic detection capabilities of a 〈012〉-cut chalcopyrite ZnGeP2 (ZGP) crystal is investigated in the terahertz (THz) frequency regime. Our experiments attest that ZGP exhibits low THz losses and dispersion, and that phonon-polariton effects are too weak to perturb the THz pulse. Additionally, ZGP is shown to have excellent phase matching between an optical probe pulse and a THz pulse. For a 1080 μm thick ZGP crystal, this phase matching yields a detection bandwidth 1.3 times greater than ZnTe and 4.8 times greater than ZnSe and GaP. Thus, ZGP has promising applications in THz time-domain spectroscopy.

Abstract-Terahertz Plasmonic Field-Induced Conductivity Modulation in Gold

A. Y. Elezzabi,

P. Maraghechi

& S. R. Greig

http://www.nature.com/srep/2015/150610/srep10812/full/srep10812.html

We report the observation of terahertz (THz) electric field induced conductivity modulation in sub-wavelength gold plasmonic media. Through all-THz pump-probe time-resolved transmission spectroscopy, we demonstrate that the presence of induced surface charges influences near-field mediated light propagation. The phenomenon is ascribed to the enhanced metal conductivity due to enhanced surface density of conduction electrons. The surface induced charge dynamics are revealed via phase-dependent time-resolved signatures. The phenomenon is a prelude to a wide class of ultrafast active THz plasmonic devices and paves the way for plasmonic field effects devices, similar to semiconductor ones.