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arXiv · 2505.24770

Phase estimation in lossy optical interferometry without a reference beam

Jun Tang·Dong-Qing Wang·Wei Zhong·Lan Zhou·Yu-Bo Sheng
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Abstract

We investigate phase estimation in a lossy interferometer using entangled coherent states, with particular focus on a scenario where no reference beam is employed. By calculating the quantum Fisher information, we reveal two key results: (1) the metrological equivalence between scenarios with and without a reference beam, established under ideal lossless conditions for the two-phase-shifting configuration,breaks down in the presence of photon loss, and (2) the pronounced inferior performance of entangled coherent states relative to NOON states, observed in the presence of a reference beam, disappears in its absence.

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Jun Tang, Dong-Qing Wang, Wei Zhong, Lan Zhou, Yu-Bo Sheng. 2025-05-30. Phase estimation in lossy optical interferometry without a reference beam. https://arxiv.org/abs/2505.24770

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