Noise-resistant phase imaging with intensity correlation

Area of Science:

• Optics and Photonics
• Metrology
• Quantum Imaging

Background:

• Interferometric methods are crucial for sensitive measurements across various scientific fields.
• Rapid phase fluctuations and low photon counts limit traditional interferometry's applicability.
• Existing solutions like shortened measurement times reduce sensitivity in low-light scenarios.

Purpose of the Study:

• To develop a phase imaging technique immune to time-dependent phase fluctuations.
• To enable high interference visibility for extended acquisition times, even in low-intensity imaging.
• To overcome the limitations of traditional interferometry in dynamic or low-light environments.

Main Methods:

• Introduced a novel phase imaging technique based on intensity correlation.
• Utilized intensity correlation instead of direct intensity measurements to recover phase information.
• Proved the method's optimality using the Cramér-Rao bound for low photon count regimes.

Main Results:

• Achieved high interference visibility irrespective of acquisition time, overcoming phase fluctuations.
• Demonstrated robustness in extreme low-photon count scenarios (≤2 photons).
• The technique is effective even with significant time-dependent phase instabilities.

Conclusions:

• The developed intensity correlation-based phase imaging technique offers a robust solution for phase measurement challenges.
• This method significantly broadens the applicability of interferometry in demanding conditions.
• Potential applications include infrared and X-ray imaging, quantum, and matter-wave interferometry.