RESUMO
Ionic motion significantly contributes to conductivity in devices such as memory, switches, and rechargeable batteries. In our work, we experimentally demonstrate that intense terahertz electric-field transients can be used to manipulate ions in a superionic conductor, namely Na^{+} ß-alumina. The cations trapped in the local potential minima are accelerated using single-cycle terahertz pulses, thereby inducing a macroscopic current flow on a subpicosecond timescale. Our results clearly show that single-cycle terahertz pulses can be used to significantly modulate the nature of superionic conductors and could possibly serve as a basic tool for application in future electronic devices.
RESUMO
We present a novel method for THz generation in lithium niobate using a reflective stair-step echelon structure. The echelon produces a discretely tilted pulse front with less angular dispersion compared to a high groove-density grating. The THz output was characterized using both a 1-lens and 3-lens imaging system to set the tilt angle at room and cryogenic temperatures. Using broadband 800 nm pulses with a pulse energy of 0.95 mJ and a pulse duration of 70 fs (24 nm FWHM bandwidth, 39 fs transform limited width), we produced THz pulses with field strengths as high as 500 kV/cm and pulse energies as high as 3.1 µJ. The highest conversion efficiency we obtained was 0.33%. In addition, we find that the echelon is easily implemented into an experimental setup for quick alignment and optimization.