Intense THz source based on BNA organic crystal pumped at conventional Ti:Sapphire wavelength

We report on high-energy terahertz pulses by optical rectification (OR) in the organic crystal N-benzyl-2-methyl-4-nitroaniline (BNA) directly pumped by a conventional Ti: sapphire amplifier. The simple scheme provides an optical-to-terahertz conversion efficiency of 0.25% when pumped by collimated laser pulses with duration of 50 fs and a central wavelength of 800 nm. The maximum output energy and electric field are 0.54 mu J and 0.5 MV/cm for 210 mu J optical pump [1].