Femtosecond Optical Pump Induced Enhancement of Terahertz Radiation from GaAs Surface

摘要

Terahertz(THz)far infrared radiation with a subpicosecond pulse duration is generated from GaAs(100)surface illuminated by femtosecond laser pulses.By illuminating the sample with another pump pulse,we observe an enhancement of THz emission.A mechanism of photocarriers trapping by impurities and defects in the depletion layer is proposed.