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Optical phase estimation in the presence of phase diffusion.
Marco G Genoni1, Stefano Olivares, Matteo G A Paris
1QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom.
Physical Review Letters
|May 17, 2011
Summary
This study explores quantum phase estimation with phase diffusion, finding optimal detection limits. Homodyne detection proves nearly optimal across various noise levels for precise optical phase measurements.
Area of Science:
- Quantum optics
- Quantum metrology
- Information theory
Background:
- Traditional optical phase measurement challenges include noiseless schemes or amplitude/detection noise.
- Phase diffusion introduces a significant hurdle in achieving high precision optical phase estimation.
Purpose of the Study:
- To investigate the ultimate quantum limits of precision for phase estimation in the presence of phase diffusion.
- To identify the optimal detection scheme for phase-shifted Gaussian states under phase diffusion.
- To derive scaling laws for quantum Fisher information and optimal squeezing fraction.
Main Methods:
- Analysis of phase-shifted Gaussian states subjected to phase diffusion.
- Derivation of quantum Fisher information and optimal squeezing fraction.
- Evaluation of detection schemes, including homodyne detection.
Main Results:
- Established quantum limits to precision for phase estimation with phase diffusion.
- Derived approximate scaling laws for quantum Fisher information and squeezing fraction concerning energy and noise.
- Identified homodyne detection as a nearly optimal scheme for both low and high noise regimes.
Conclusions:
- Phase diffusion significantly impacts optical phase estimation precision.
- Homodyne detection offers a robust and near-optimal strategy for phase estimation across a wide range of noise conditions.
- The derived scaling laws provide valuable insights into optimizing quantum metrology protocols.
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