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 $\sim 10\text{kV}/\text{cm}$ . 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.