TERAHERTZ OPTICAL RECTIFICATION

We present experimental measurements of Terahertz optical rectification in electro-optic crystals. The measured data was compared with a simple theoretical analysis (anharmonic oscillator model). We also measured Terahertz-bandwidth subpicosecond electromagnetic radiation via nearly-degenerate difference-frequency generation in electrooptic materials. The variation in Terahertz emission with crystal orientation demonstrated that the generation of Terahertz radiation via optical rectification involves a bulk second-order nonlinear process. We studied Terahertz optical rectification from zincblende crystals as the incident photon energy was tuned across the semiconductor optical absorption band-edge (resonant excitation). We also present the measurement of temperature-dependent Terahertz optical rectification. A comparison between the two second-order nonlinear processes, sum-frequency generation (second-harmonic generation) and different-frequency generation (optical rectification) is presented.