High-field THz pulses from a GaAs photoconductive emitter for non-linear THz studies
Abhishek Singh, Jiang Li, Alexej Pashkin, Rakesh Rana, Stephan Winnerl, M. Helm, H. Schneider
Abstract
We report the emission of high-field terahertz pulses from a GaAs large-area photoconductive emitter pumped with a Ti:Sapphire amplifier laser system at 800 nm wavelength and 1 kHz repetition rate. The maximum estimated terahertz electric field at the focus is ≳ 230 kV/cm. We also demonstrate the capability of the terahertz field to cause a non-linear effect, which usually requires high-field terahertz pulses generated through optical rectification or an air plasma. A significant drop in the optical conductivity of optically pumped GaAs due to Γ-L inter-valley scattering of free electrons caused by the strong THz field is found.
Topics & Concepts
Terahertz radiationOpticsMaterials scienceOptoelectronicsOptical rectificationLaserCommon emitterElectric fieldTerahertz spectroscopy and technologyPhotoconductivityPhotomixingFemtosecondFar-infrared laserNonlinear opticsPhysicsTerahertz metamaterialsQuantum mechanicsTerahertz technology and applicationsGyrotron and Vacuum Electronics ResearchSuperconducting and THz Device Technology