Video recording true single-photon double-slit interference

TL;DR

This paper demonstrates a method for directly recording video of single-photon double-slit interference by reducing camera noise through heralded photon detection, enabling clearer visualization of quantum interference phenomena.

Contribution

It introduces a heralded detection scheme that allows real-time video imaging of single-photon interference, advancing experimental capabilities in quantum optics.

Findings

Successful video recording of single-photon double-slit interference.

Enhanced understanding of spatial coherence and photon correlations.

Illustrations of ghost imaging and diffraction phenomena.

Abstract

As normally used, no commercially available camera has a low-enough dark noise to directly produce video recordings of double-slit interference at the photon-by-photon level, because readout noise significantly contaminates or overwhelms the signal. In this work, noise levels are significantly reduced by turning on the camera only when the presence of a photon has been heralded by the arrival, at an independent detector, of a time-correlated photon produced via parametric down-conversion. This triggering scheme provides the improvement required for direct video imaging of Young's double-slit experiment with single photons, allowing clarified versions of this foundational demonstration. Further, we introduce variations on this experiment aimed at promoting discussion of the role spatial coherence plays in such a measurement. We also emphasize complementary aspects of single-photon measurement, where imaging yields (transverse) position information, while diffraction yields the transverse momentum, and highlight the roles of transverse position and momentum correlations between down-converted photons, including examples of "ghost" imaging and diffraction. The videos can be accessed at http://sun.iwu.edu/~gspaldin/SinglePhotonVideos.html online.