Nanoradian-Scale Precision in Light Rotation Measurement via Indefinite Quantum Dynamics

TL;DR

This paper demonstrates a novel quantum approach using indefinite time direction to achieve nanoradian-scale precision in light rotation measurement, surpassing previous methods and enhancing optical metrology capabilities.

Contribution

Introduces a quantum strategy leveraging indefinite time direction to maximize resource utilization for ultra-precise light rotation measurement.

Findings

Achieved nanoradian-scale rotation measurement precision.

Demonstrated the effectiveness of indefinite quantum dynamics in optical metrology.

Surpassed previous precision limits in light rotation measurement.

Abstract

The manipulation and metrology of light beams are pivotal for optical science and applications. In particular, achieving ultra-high precision in the measurement of light beam rotations has been a long-standing challenge. Instead of utilizing quantum probes like entangled photons, we address this challenge by incorporating a quantum strategy called "indefinite time direction" into the parameterizing process of quantum parameter estimation. Leveraging this quantum property of the parameterizing dynamics allows us to maximize the utilization of OAM resources for measuring ultra-small angular rotations of beam profile. Notably, a nanoradian-scale precision of light rotation measurement is finally achieved in the experiment, which is the highest precision by far to our best knowledge. Furthermore, this scheme holds promise in various optical applications due to the diverse range of manipulable resources offered by photons.