APL Photonics (Jul 2022)

Fast and efficient demultiplexing of single photons from a quantum dot with resonantly enhanced electro-optic modulators

  • Julian Münzberg,
  • Franz Draxl,
  • Saimon Filipe Covre da Silva,
  • Yusuf Karli,
  • Santanu Manna,
  • Armando Rastelli,
  • Gregor Weihs,
  • Robert Keil

DOI
https://doi.org/10.1063/5.0091867
Journal volume & issue
Vol. 7, no. 7
pp. 070802 – 070802-10

Abstract

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We report on a multi-photon source based on active demultiplexing of single photons emitted from a resonantly excited GaAs quantum dot. Active temporal-to-spatial mode demultiplexing is implemented via resonantly enhanced free-space electro-optic modulators, making it possible to route individual photons at high switching rates of 38 MHz. We demonstrate routing into four spatial modes with a high end-to-end efficiency of ≈ 79% and measure a four-photon coincidence rate of 0.17 Hz mostly limited by the single-photon source brightness and not by the efficiency of the demultiplexer itself. We use the demultiplexer to characterize the pairwise indistinguishability of consecutively emitted photons from the quantum dot with variable delay time.