Direct measurement of the spatial Wigner function with area-integrated detection

Area of Science:

• Quantum Optics
• Optical Metrology

Background:

• Characterizing spatial coherence is crucial for understanding and manipulating light beams.
• Traditional methods may require complex or unavailable array detectors.
• The Wigner distribution function offers a powerful theoretical framework for optical analysis.

Purpose of the Study:

• To introduce and experimentally validate a novel technique for measuring transverse spatial coherence.
• To provide an alternative method for coherence characterization, especially when array detectors are not feasible.
• To explore the quantum-optical implications and potential applications of the developed technique.

Main Methods:

• Utilizing the Wigner distribution function for coherence characterization.
• Employing interference measurements between rotated and displaced beam replicas.
• Using an area-integrating detector for signal acquisition.

Main Results:

• Successful experimental demonstration of the novel coherence characterization technique.
• Achieved optimal signal-to-noise ratio, outperforming other methods in specific regimes.
• Analysis of the quantum-optical picture for single-photon signals.

Conclusions:

• The presented method offers an effective and robust approach to measuring transverse spatial coherence.
• The technique is particularly advantageous in scenarios lacking advanced array detectors.
• Potential applications in quantum information processing and related fields were identified.