Coherent vs incoherent emission from resonantly excited semiconductor heterostructures: a new probe using femtosecond interferometric techniques

The discrimination between the coherent (Rayleigh scattering) or incoherent (photoluminescence) light emission from semiconductor heterostructures after resonant excitation is still an open problem when exciton lifetimes are investigated by means of time-resolved luminescence techniques. An interferometric correlation technique with femtosecond time resolution capable of discriminating between coherent or incoherent light emission is described and experimental results are reported for both bulk and quantum well structures.