High-dimensional two-photon interference effects in spatial modes

TL;DR

This paper explores two-photon interference effects in high-dimensional spatial modes, demonstrating advanced quantum interference phenomena and potential for stable, complex quantum optical networks without interferometric stability requirements.

Contribution

It introduces a method to observe two-photon interference in high-dimensional spatial modes within a single beam-path, extending quantum interference control to multi-dimensional modes.

Findings

Demonstrated Hong-Ou-Mandel interference in spatial modes

Extended interference effects to three and four-dimensional modes

Showed stability advantages of spatial mode operations

Abstract

Two-photon interference is a fundamental quantum optics effect with numerous applications in quantum information science. Here, we study two-photon interference in multiple transverse-spatial modes along a single beam-path. Besides implementing the analogue of the Hong-Ou-Mandel interference using a two-dimensional spatial-mode splitter, we extend the scheme to observe coalescence and anti-coalescence in different three and four-dimensional spatial-mode multiports. The operation within spatial modes, along a single beam-path, lifts the requirement for interferometric stability and opens up new pathways of implementing linear optical networks for complex quantum information tasks.