Distribution of exciton binding-energies in disordered semiconductor quantum-wells

Summary form only given. Partly non-degenerate four-wave mixing is able to detect coherent coupling between excitonic resonances like e.g. light-hole and heavy-hole excitons or between an exciton and its continuum states. We apply an extension of this method, which we call selective coherent spectroscopy (SCS), to symmetrically strained (GaIn)As/Ga(PAs) multiple quantum-wells. The samples are excited simultaneously by a picosecond pulse with wavevector k/sub 1/ and a 100 fs pulse with wavevector k/sub 2/. The central wavelength of the picosecond pulse is scanned over the entire spectrum of the 100 fs pulse and the four-wave mixing signal in the direction 2k/sub 2/-k/sub 1/ is detected at a fixed energy. This scan provides an SCS spectrum.