Single-cycle strong terahertz pulse generation from a vacuum-plasma interface driven by intense laser pulses.
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.
Dong
X G
XG
Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190, China.
Sheng
Z M
ZM
Wu
H C
HC
Wang
W M
WM
Zhang
J
J