Advantage of Coherent States in Ring Resonators over Any Quantum Probe Single-Pass Absorption Estimation Strategy

TL;DR

This paper demonstrates that coherent states in ring resonators can surpass quantum probes in absorption estimation, leveraging interference and resonance effects, and match the performance of bright squeezed states under optimal conditions.

Contribution

It reveals the advantage of coherent states in ring resonators over quantum probes, highlighting their potential for enhanced absorption measurement strategies.

Findings

Coherent states outperform quantum probes in ring resonator absorption estimation.

Under optimal conditions, coherent states match bright squeezed probe performance.

Resonance effects significantly enhance measurement precision.

Abstract

Quantum states of light have been shown to enhance precision in absorption estimation over classical strategies. By exploiting interference and resonant enhancement effects, we show that coherent-state probes in all-pass ring resonators can outperform any quantum probe single-pass strategy even when normalized by the mean input photon number. We also find that under optimal conditions coherent-state probes equal the performance of arbitrarily bright pure single-mode squeezed probes in all-pass ring resonators.