Abstract

The manipulation of charged particles and charged-particle beams requires THz pulses with up to multi-mJ energy and 10 MV/cm peak electric field [1–3]. In our experiments [4], efficient generation of THz pulses with high energy was demonstrated by optical rectification of 785-fs laser pulses in LiNbO₃ (LN) using tilted-pulse-front pumping (TPFP) (Fig. 1a). The enhancement of pump-to-THz conversion efficiency by a factor of 2.4 to 2.7 was demonstrated up to 186 μJ THz energy by cryogenic cooling of the LN crystal and using up to 24 GW/cm² pump intensity. Generation of THz pulses with more than 0.4 mJ energy and 0.77% efficiency was demonstrated even at room temperature by increasing the pump intensity to 240 GW/cm². The THz spectral peak is decreasing from about 0.25 THz to 0.14 THz with increasing energy (Fig. 1a, inset).

© 2015 IEEE