Study of harmonic generation from InSb excited by terahertz wave pulses with femtosecond pulse laser excitation

The excited density dependences for InSb by intense terahertz pulses whose central frequency is 0.5 THz with femtosecond pulse laser excitation were investigated in detail. The transmitted terahertz waveforms with perpendicular polarization to incident beam change drastically at the low- and high-density excitations. The third harmonic generation around 1.5 THz is observed.