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.
- Received 15 December 2021
- Revised 24 March 2022
- Accepted 5 May 2022
DOI:https://doi.org/10.1103/PhysRevLett.128.230501
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