We report on high-field terahertz transients with 0.9-mJ pulse energy produced in a 400 mm(2) partitioned organic crystal by optical rectification of a 30-mJ laser pulse centered at 1.25 mu m wavelength. The phase-locked single-cycle terahertz pulses cover the hard-to-access low-frequency range between 0.1 and 5 THz and carry peak fields of more than 42 MV/cm and 14 Tesla with the potential to reach over 80 MV/cm by choosing appropriate focusing optics. The scheme based on a Cr:Mg2SiO4 laser offers a high conversion efficiency of 3% using uncooled organic crystal. The collimated pump laser configuration provides excellent terahertz focusing conditions. (C) 2014 Optical Society of America
Fabrizio Carbone, Giovanni Maria Vanacore, Ivan Madan, Ido Kaminer, Simone Gargiulo, Francesco Barantani