Fiber-compatible photonic feed-forward with 99% fidelity

TL;DR

This paper demonstrates a fiber-compatible measurement and feed-forward scheme for photonic quantum systems at telecom wavelengths, achieving 99% fidelity, enabling advanced quantum communication and computing applications.

Contribution

The work introduces a fiber-compatible measurement and feed-forward method with high fidelity, suitable for integration into existing fiber-optic quantum networks.

Findings

Achieved 99% measurement and feed-forward fidelity after corrections.

Demonstrated deterministic control of photon paths using ultrafast optical switches.

Validated the scheme's applicability for quantum computing and communication.

Abstract

Both photonic quantum computation and the establishment of a quantum internet require fiber-based measurement and feed-forward in order to be compatible with existing infrastructure. Here we present a fiber-compatible scheme for measurement and feed-forward, whose performance is benchmarked by carrying out remote preparation of single-photon polarization states at telecom-wavelengths. The result of a projective measurement on one photon deterministically controls the path a second photon takes with ultrafast optical switches. By placing well-calibrated {bulk} passive polarization optics in the paths, we achieve a measurement and feed-forward fidelity of (99.0 $\pm$ 1)%, after correcting for other experimental errors. Our methods are useful for photonic quantum experiments including computing, communication, and teleportation.