Time Resolved Amplitude and Phase of Coherent Four Wave Mixing Emission from GaAs Quantum Wells

Abstract

Time integrated and time-resolved four wave mixing (FWM) techniques using ultrashort pulses have proven to be extremely powerful tools for studying coherent processes and excitonic effects in semiconductors and semiconductor multiple quantum wells (MQWs). These techniques have provided considerable information about the time dependent amplitude of the emitted FWM signal, but they provide no information about the time dependent phase. Complete characterization of the emitted electromagnetic field requires the measurement of both amplitude and phase. Moreover, it has been emphatically demonstrated1 that the phase dynamics carry essential information about the optical interactions and the fundamental processes. Consequently, failure to measure the phase will result in a loss of this information.