Strong terahertz radiation from relativistic laser interaction with   solid density plasmas
  We report a plasma-based strong THz source generated by using intense femtosecond laser pulses to irradiate solid targets at relativistic intensity >10^18W/cm2. Energies up to 50 microJ/sr per THz pulse is observed in the specular direction when the laser pulses are incident onto a copper foil at 67.5 degree. The source appears to be linearly polarized. The temporal, spectral properties of the THz are measured by a single shot, electro-optic sampling method with a chirped laser pulse. The THz radiation is attributed to the self-organized transient fast electron currents formed along the target surface. Such a strong THz source allows potential applications in THz nonlinear physics. 
Y. T. Li, C. Li, M. L. Zhou, W. M. Wang, F. Du, W. J. Ding, X. X. Lin,   F. Liu, Z. M. Sheng, L. M. Chen, J. L. Ma, X. Lu, Q...
physics.optics physics.plasm-ph