Generation of TW-Class THz Sources from Picosecond Laser-Solid Interactions

High intensity (>10¹⁸ W/cm²) laser–matter interactions have been found to be efficient (>0.1%) sources of terahertz (THz) radiation using a wide variety of solid targets irradiated by currently available lasers with picosecond-scale pulses. We present the results of several years of study using foil, wire and microchannel targets irradiated with the joule-class Multi-Terawatt laser and kilojoule-class OMEGA EP laser. THz radiation measurements were performed with a custom-designed, EMP-hardened pyrometer. The experiments were observed to generate THz sources in the range of 10’s of millijoules to greater than 1 joule of pulse energy, which correspond to a terawatts in peak power. The physics of THz generation from each target type is examined analytically and compared to the experimental results. Future uses of these powerful THz sources are discussed, with an emphasis on extreme light–matter interactions using powerful THz sources to drive matter into new states as well as a probe of carrier and molecular dynamics in HED materials.