Nonlinear spectroscopy using intense THz pulses with amplitudes exceeding 1 MV/cm

摘要

Recent development of ultra-short pulse technologies allows us to drive large amplitude motion of electron and ion coherently. The intense terahertz (THz) pulse resonant with the vibration frequency is promising to drive vibrations more directly and in coherent manner. In the case of semiconductors, one may coherently control the electronic system in the sub-level structures of quantum structures with intense THz waves. We recently performed the generation of intense terahertz pulse using tilted wave-front technique with a Ti:Sapphire regenerative amplifier [1]. Figure 1 shows typical time-profile of the electric field of the intense THz pulse: The maximum electric field is larger than 1 MV/cm (@1THz), which ponderomotive energy is as large as 10 eV. The ponderomotive energy is strong enough to ionize bound electronic states in solids such as donors and accepters and easy to induce nonlinear optical effects in solids [2,3].