Nonlinearity in Indium Phosphide using THz Radiation

In this abstract, a brief summary of Terahertz (THz) generated by two color mixing which induced nonlinearity in semiconductor is presented. Indium Phosphide have shown saturable absorption like behavior with MV/cm THz field strengths. The free carriers, which are generated by leading edge of THz pulse, achieve high kinetic energies. These energetic carriers in lowest intervalley of the conduction band get scattered in to next highest intervalley of the conduction band. The effective mass of the electrons in these valleys reduce leading to decrease in the conductivity of the sample increasing the high transmission of the THz at focus.