THz Nonlinear Spectroscopy of Solids

We present a review of the recent progress in the generation methods of intense terahertz (THz) single-cycle pulses and their application to THz nonlinear spectroscopy in condensed matters. Special attentions are paid to various aspects of nonlinearity in semiconductors including dynamical Franz-Keldysh effect, ballistic acceleration of free carriers, and coherent control of the exciton system.