Abstract

Two-beam four-wave mixing (FWM) experiments on bulk GaAs at low temperatures using pulses of 15 fs in duration have recently revealed two observations: i) non-Markovian relaxation resulting from exciton-LO-phonon interaction¹ at intermediate carrier densities (≈10¹⁶ cm^-3) and ii) an apparent contradiction between the observed decay in the time delay domain and the FWM-linewidth² at densities as low as a few 10¹⁴ cm^-3. This apparent contradiction, which has previously only been observed on Fano-resonances,³ has had no explanation up to this point.

© 1996 Optical Society of America