Picosecond dynamics of spin-related optical nonlinearities in InxGa1-xAs multiple quantum wells at 1064 nm

Light-induced absorption and diffraction measurements of resonantly excited 10-nm-width InGaAs multiple quantum wells have been carried out, using circularly polarized beams at 1064 nm. Spin relaxation time tau(s)similar or equal to280+/-15 ps has been determined by monitoring dynamics of light absorption bleaching at 0.04 mJ/cm(2), while a nonlinearly compressed spin component in diffraction varied from 220+/-20 ps to 115+/-15 ps with excitation. The kinetics of carrier grating with randomized spins allowed the determination of the bipolar diffusion coefficient D=11.5 cm(2)/s, hole mobility of 230 cm(2)/V s, and carrier lifetime tau(R)=0.73-1 ns. (C) 2004 American Institute of Physics.