Dynamics of Photoexcited Picosecond Space-Charge Fields with Hot Electron Nonlinear Transport in DC-Biased Semi-Insulating GaAs

Abstract

Picosecond transient characteristics of photocarriers and space-charge fields excited by single-shot picosecond pulses at 1.064 µ m in high-dc-biased GaAs are analyzed by means of the band transport rate equations. Numerical simulations are performed and their results are compared with approximate analytic results. In particular, the effects of hot electron nonlinear transport on the dynamics of photocarriers and space-charge fields are discussed. It is found that the application of high dc electric fields results in an increase of decay rates of photocarriers and space-charge fields and induces oscillatory behaviors in their decay dynamics under certain conditions. It is also found that the space-charge field can be enhanced considerably by the hot electron nonlinear transport and its cause is attributed to an increase of the electron temperature.