Computer Simulations of Pulsed-Laser Induced Coherent Plasma Oscillations in GaAs Crystals

概要

論文の詳細を見る
One-dimensional transport equations for pulsed-laser induced space-charge distributions inGaAs crystals have been computed using a finite difference procedure by two models; (a) ModelA for 7-GaAs with an applied dc electric field under a uniform illumination over the crystal and(b) Model B for n- and 7-GaAs without the electric field under a half illumination to simulatethe "transient thermoelectric effect" (TTB). With Model A, the temporal and spatial evolu-tions of restored space-charge density of photoexcited electrons and holes are obtained, fromwhich an induced electric field is found to oscillal,e with a sirngle frequency of plasma oscillations(0.3 -2 THz), in satisfactory agreement with reported experiments. Model B calculations haverevealed that near the boundary between the illuminated and non-illuminated regions, the ap-preciable enhancement of space-charge densities and induced electric fields are observed, whichdiffuse or drift toward a positive x direction, showing characteristic damping oscillations withtwo frequency components fg dtne to the doped donor electrons and /l due to the doped andphotoexcited electrons of plasma oscillations. Furthermore, the induced TTE voltages measuredacross both ends of the crystal without dc electric field are simulated to show similar coherentplasma oscillations.
社団法人日本物理学会の論文
1996-03-15