A source of THz radiation with electric field strength of more than 1 MV cm-1 on the basis of 100-Hz femtosecond Cr : forsterite laser system

A source of terahertz (THz) radiation with a bandwidth of 0.5–2.5 THz and a pulse repetition rate of 100 Hz has been developed. The THz generation is based on optical rectification of femtosecond pulses (generated by a Cr : forsterite laser system) in a nonlinear organic crystal OH1. An optical scheme of a multipass amplifier for the Cr : forsterite laser system is developed to increase the pulse energy to 2.2 mJ. The conversion efficiency for pump laser radiation at a wavelength of 1.24 μm into THz radiation is found to be to 2%. An electric field strength of 3.5 MV cm^-1 is attained when focusing a THz beam into a near diffraction-limited spot.