title: Single-cycle strong terahertz pulse generation from a vacuum-plasma interface driven by intense laser pulses.
abstract: Single-cycle strong terahertz pulses can be generated by irradiating ultrashort intense laser pulses onto a tenuous plasma slab. At the plasma surface, laser ponderomotive force accelerates electrons and induces net currents, which radiate terahertz pulses. Our theoretical model suggests that if tau_{L}>2pi/omega_{p}, with tau_{L} as the laser-pulse duration and omega_{p} as the plasma frequency, the emission frequency is around tau_{L};{-1}. On the other hand, the emission frequency is around omega_{p}/2pi if tau_{L}<2pi/omega_{p}. Our numerical simulations support the theoretical model, showing that such a terahertz source is capable of providing megawatt power, field strengths of MV/cm, and broad frequency tunability.
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190, China.
authors.forename: X G
authors.initials: XG
authors.lastname: Dong
authors.forename: Z M
authors.initials: ZM
authors.lastname: Sheng
authors.forename: H C
authors.initials: HC
authors.lastname: Wu
authors.forename: W M
authors.initials: WM
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Zhang