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

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 approximate to 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. (c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

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, allowing for routing individual photons at a high switching rate of 38 MHz. The study demonstrates efficient routing into four spatial modes with an end-to-end efficiency of approximately 79% and measures a four-photon coincidence rate of 0.17 Hz, mainly limited by the brightness of the single-photon source rather than the efficiency of the demultiplexer itself. The demultiplexer is used to characterize the pairwise indistinguishability of consecutively emitted photons from the quantum dot with variable delay time.