Characteristics of ultrafast response induced by impulsive interference of excitons in a GaAs/AlAs multiple quantum well on a slightly strained buffer layer

Ultrafast responses caused by ultrashort pulse excitation can be applied to ultrafast optical switches with high-speed information processing. In this paper, via the impulsive interference of excitons, we achieve an ultrafast optical response suited for ultrafast switches in all-optical networks. Due to the simultaneous excitation of two exciton states in the multiple quantum well on a strained buffer layer without the occurrence of adverse effects like stacking faults, impulsive interference is induced. The small compressive strain from the buffer layer modifies the orientation of the excitons inside the quantum well, and causes the ultrafast response.