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

TL;DR

This paper presents a high-efficiency active demultiplexer for single photons emitted from a quantum dot, enabling rapid routing and characterization of photon indistinguishability, advancing quantum photonic technologies.

Contribution

The work introduces a resonantly enhanced electro-optic demultiplexer capable of routing single photons at 38 MHz with high efficiency, improving multi-photon source scalability.

Findings

Achieved 79% end-to-end efficiency in routing photons into four modes.

Demonstrated a four-photon coincidence rate of 0.17 Hz.

Characterized photon indistinguishability with variable delay.

Abstract

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 demultipexing 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.