We demonstrate large nonlinear terahertz responses in the gaps of metamaterial split ring resonators in several materials and use nonlinear THz transmission and THz-pump/THz-probe spectroscopy to study the nonlinear responses and dynamics. We use the field enhancement in the SRR gaps to initiate high-field phenomena at lower incident fields. In vanadium dioxide, we drive the insulator-to-metal phase transition with high-field THz radiation. The film conductivity increases by over two orders of magnitude and the phase transition occurs on a several picosecond timescale. In gallium arsenide, we observe high-field transport phenomena, including mobility saturation and impact ionization. The carrier density increases by up to ten orders of magnitude at high fields. At the highest fields, we demonstrate THz-induced damage in both vanadium dioxide and gallium arsenide.
|Original language||English (US)|
|Title of host publication||18th International Conference on Ultrafast Phenomena, UP 2012|
|State||Published - 2013|
|Event||18th International Conference on Ultrafast Phenomena, UP 2012 - Lausanne, Switzerland|
Duration: Jul 8 2012 → Jul 13 2012
|Name||EPJ Web of Conferences|
|Other||18th International Conference on Ultrafast Phenomena, UP 2012|
|Period||7/8/12 → 7/13/12|
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