Nonlinear Optical Phenomena Induced by Intense Single-Cycle Terahertz Pulses

Recent developments in high-power table-top terahertz (THz) pulse sources enable us to coherently drive low-energy transitions into the nonlinear regime and to study fascinating nonlinear effects in various materials. This paper describes a tilted-pulse-front pumping scheme with a LiNbO₃ crystal to generate intense single-cycle THz pulses. This scheme is capable of generating intense single-cycle THz pulses inducing strong spectral modulations in the excitonic and band-edge absorption of ZnSe/ZnMgSSe multiple quantum wells (MQW). Furthermore, it is shown that a 1 MV/cm electric field of a THz pulse allows us to excite electrons from the valence to conduction band of GaAs/AlGaAs MQW and observe a bright exciton luminescence.