Femtosecond probe-probe transmission studies of LT-grown GaAs near the band edge

摘要

We have studied the near-edge optical response of a LT-grown GaAs sample which was deposited at 300(degrees)C on a Si substrate, and then annealed at 600(degrees)C. The Si was etched away to leave a 1 micrometer free standing GaAs film. Femtosecond transmission measurements were made using an equal pulse technique at four wavelengths between 825 and 870 nm. For each wavelength we observe both a multipicosecond relaxation time, as well as a shorter relaxation time which is less than 100 femtoseconds.