An electrically driven microcavity single photon source

Abstract

Single photon sources are important components for future quantum communication networks. Lights emitting diodes with emission from an embedded self-organized quantum dot offer compact semiconductor sources that can be easily fabricated using standard photolithographic techniques. In this paper, progress towards an electrically driven 1300 nm quantum dot single photon emitter for fiber optic based applications are addressed. Low density longer wavelength emissions were achieved by exploiting the second critical growth threshold for large self-assembled InAs quantum dots on GaAs. The single photon collection efficiency was improved by incorporating the quantum dots between GaAs/AlxGa1-xAs distributed Bragg reflector mirror stacks and laterally confined inside etched micropillars. Resonance of the microcavity mode with the InAs quantum dot emission leads to an enhancement in the collection intensity. Emission from an active quantum dot was collected using a confocal microscope and coupled directly into a single mode fiber. Strong suppression in the multiphoton emission rate was verified by a custom Hanbury-Brown and Twiss interferometer set-up with optical fibers and InGaAs single photon avalanche photodetectors. Integration of electrical contacts with a planar resonant microcavity structure for a single photon light emitting diode is also discussed. Electroluminescence spectra recorded on such a device revealed sharp lines due to the charge recombination in a quantum dot. Correlation measurements on a single quantum dot line showed the suppression of multiphoton emission for an electrically driven source near 1300 nm for the first time.