Description
Ultraintense laser-plasma interactions offer a novel approach to generating high-power terahertz (THz) radiation, and have aroused ever-increasing interest. This talk will review the latest progress on the ultraintense laser-driven THz radiation from plasmas. TW-scale THz bursts have been demonstrated experimentally by irradiating a thin foil with a high-intensity femtosecond or picosecond laser pulse. By tuning the laser or target parameters, the THz spectra can be tuned effectively over a wide range of 1~20 THz, and the laser-to-THz energy conversion efficiency can be boosted up to ~1%. Recently, the tens-of-femtoseconds duration and ultrafast recirculation dynamics of fast electrons have been revealed from the THz self-emission, demonstrating a novel in-situ diagnostic of laser plasmas. Such extreme THz pulses enable the previously inaccessible relativistic optics in the THz regime. Recent studies on the THz plasmas, including the strong-field THz ionization of dielectrics, anomalous plasma-induced THz self-focusing, and ionization-induced THz transparency, will also be presented.