Combining a scanning near-field optical microscope with a picosecond streak camera: Statistical analysis of exciton kinetics in GaAs single-quantum wells

Combining a low-temperature scanning near-field optical microscope with a picosecond streak camera allows us to measure the complete wavelength-time behavior at one spot on the sample within about 13 min at excitation powers of 100 nW. We use this instrument to measure the variation of relaxation times in disordered single-GaAs quantum wells with sample position.