We use two-photon excitation to create biexcitonic complexes with two electron-hole pairs in different orbital levels of a GaAs/AlAs quantum dot. In addition to p-shell emission of the biexcitonic triplet states generated by two-photon excitation, we observe additional higher-energy resonances which are a signature of the radiative cascade of two-photon excited singlet states. The detection of these signals obtained in a high excitation regime is made possible by the use of a waveguiding structure in which the quantum dots are inserted, allowing an orthogonal excitation and detection geometry with an excellent laser rejection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.