Intense narrow band terahertz generation via type-II difference-frequency generation in ZnTe using chirped optical pulses

We developed a tabletop source of intense, narrow band terahertz pulses via type-II difference-frequency generation in ZnTe crystal using two linearly chirped and orthogonally polarized optical pulses. The pulse energy is in the range of 1-3 nJ depending on the variable pulse duration from 1 to 5 ps. The amplitude of electric field reaches ∼ 10 kV / cm . The central frequency of the spectrum is continuously tunable from 0.3 to 2.5 THz with the bandwidth at 0.2-0.5 THz.