Recently Terahertz (THz) radiation from laser-produced plasmas has attracted much interest since plasmas can work at arbitrarily high laser intensity. We have systematically studied strong THz radiation from solid targets driven by ultraintense laser pulses.  The experiments were performed with femtosecond and picosecond laser facilities respectively. The energetic MeV fast electron beams accelerated by the high intensity laser pulses are the origin for the THz radiation. When the forward electrons reach the target rear surface, THz radiation can be induced due to transition radiation. We have demonstrated the total energy of THz pulses emitted from the target rear is up to ~200 mJ, giving a peak power upto ~Terawatt, when using 60J ps driving laser beam. We have tried to use the laser-plasma interactions based THz radiation to study the fast electron dynamics, water and protein dynamics. In this talk we will show some preliminary results of THz applications.
 

high peak power Terahertz radiation, ultraintense laser plasma interactions