Electro-optic nature of ultrafast pump-probe reflectivity response from multilayer semiconductor heterostructures

摘要

We provide the evidence for the electro-optic nature of the transient reflectivity change (TRC) response from GaAs/GaSb/InAs heterostructures measured in ultrafast pump-probe experiments. The evidence is based on the correlation between TRC and the transient electric-field-induced second harmonic generation change signals, which have been measured simultaneously. The TRC signal is induced through the second- and third-order nonlinearities by the interfacial dc electric fields originating from the charge separation of pump-excited carriers among the layers. The effect of the interface type between GaSb and InAs layers on the interfacial field strength was analyzed.