为研究空穴对自旋极化电子扩散的影响,提出用自旋密度光栅方法来观察电子自旋扩散过程。由飞秒激光在本征GaAs多量子阱中激发产生瞬态自旋光栅和瞬态自旋密度光栅,并用于研究电子自旋扩散和电子自旋双极扩散。实验测得自旋双极扩散系数D as=25.4 cm2/s,低于自旋扩散系数D s=113.0 cm2/s,表明自旋密度光栅中电子自旋扩散受到空穴的显著影响。 In order to study the effect of holes on the spin-polarized electron diffusion, a spin-density grating method is proposed to observe the electron spin diffusion. The transient spin grating and transient spin density grating are excited by the femtosecond laser in the intrinsic GaAs multiple quantum well and used to study the electron spin diffusion and electron spin bipolar diffusion. The measured spin dipole diffusion coefficient D as = 25.4 cm2 / s, which is lower than the spin diffusion coefficient D s = 113.0 cm2 / s, shows that the electron spin diffusion in the spin density grating is significantly affected by the holes.