Cumulative ejection of terahertz radiation from a laser-driven magnetized plasma

Abstract

We propose a scheme for efficient directional emission of laser-driven wakefields from a magnetized plasma. In the scheme, a laser–plasma interaction region is sandwiched between a pair of dielectric prisms of total internal reflection. The wakefields, propagating in the plasma at different angles to the laser beam, are cumulated by the prisms and radiated to free space in the direction of the laser beam. For magnetic fields <100 T, a 50-fs laser pulse with 1-J energy can generate long lasting (hundreds of ps) multicycle terahertz radiation with mJ-level energy. For a 500-T field, the laser pulse can generate terahertz bursts with a uniform spectrum in the ∼7–14 THz interval with ten-mJ-level energy.