Abstract-GV/m single-cycle terahertz fields from a laser-driven large-size partitioned organic crystal

C. Vicario, B. Monoszlai, and C. P. Hauri

https://journals.aps.org/prl/accepted/c7079Yf5Cf718537276d86f4c4bdf3efaa38d538e

We report on compact and efficient laser-based THz generation in the Terahertz frequency gap (1-10 THz). The radiation is generated by optical rectification of a mid-infrared laser in a large-size, partitioned nonlinear organic crystal assembly. This enables up-scaling of presently field-limited table-top THz sources to GV/m electric and several Tesla magnetic field at millijoule pulse energy. In agreement with simulations the THz beam properties at focus are shown to be not deteriorated by the discontinuity of the emitter surface. The high laser-to-THz energy conversion efficiency exceeds the Manley-Rowe limit and is explained by a cascaded chi^(2) process in the organic crystals accompanied by a significant red shift of the pump spectrum. The scheme provides a compact, table-top THz source for single-cycle transients at field strength equivalent or even higher to linear accelerator and FEL-based THz sources. This opens an avenue towards novel nonlinear THz applications.