Talbot self-imaging and two-photon interference in ring-core fibers

TL;DR

This paper experimentally demonstrates Talbot self-imaging and two-photon interference in ring-core fibers, revealing their potential for advanced optical and quantum information applications.

Contribution

It reports the first observation of cylindrical Talbot carpets and shows that ring-core fibers can serve as high-order beamsplitters for single photons.

Findings

Observation of cylindrical Talbot carpets in ring-core fibers

Controlled two-photon interference using the fiber as a beamsplitter

Potential for scalable quantum and classical optical networks

Abstract

Wave propagation on the surface of cylinders exhibits interferometric self imaging, much like the Talbot effect in the near-field diffraction at periodic gratings. We report the experimental observation of the cylindrical Talbot carpet in weakly-guiding ring-core fibers for classical light fields. We further show that the ring-core fiber acts as a high-order optical beamsplitter for single photons, whose output can be controlled by the relative phase between the input light fields. By also demonstrating high-quality two-photon interference between indistinguishable photons sent into the ring-core fiber, our findings open the door to applications in optical telecommunications as a compact beam multiplexer as well as in quantum information processing tasks as a scalable realization of a linear optical network.