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.
|Journal||E P J Web of Conferences|
|Number of pages||3|
|Publication status||Published - 2013|
|Event||18th International Conference on Ultrafast Phenomena (UP 2012) - Lausanne, Switzerland|
Duration: 8 Jul 2012 → 13 Jul 2012
|Conference||18th International Conference on Ultrafast Phenomena (UP 2012)|
|Period||08/07/2012 → 13/07/2012|