Young's Double-Slit Interference Demonstration with Single Photons

Abstract: The interference of single photons going through a double slit is a compelling demonstration of the wave and particle nature of light in the same experiment. Single photons produced by spontaneous parametric down-conversion can be used for this purpose. However, it is particularly challenging to implement due to coherency and resolution challenges. In this article, we present a tabletop laboratory arrangement suitable for the undergraduate instruction laboratory that overcomes these challenges. The apparatus scans a single detector to produce a plot showing the interference patterns of single photons. We include experimental data obtained using this setup demonstrating double-slit and single-slit interference as well as quantum erasing through the use of sheet polarizers.