Correcting for accidental correlations in saturated avalanche photodiodes

Area of Science:

• Quantum optics
• Photon detection

Background:

• Accidental coincidences in photon detection reduce signal quality.
• Detector saturation, common at high event rates, complicates coincidence measurements.

Purpose of the Study:

• To develop a general method for estimating accidental coincidence rates in saturated single photon detectors.
• To improve signal-to-noise ratios in coincidence measurements.

Main Methods:

• Developed an "effective duty cycle" model incorporating detector recovery times.
• Modeled passively quenched avalanche photodiodes.
• Applied post-processing to experimental data.

Main Results:

• Demonstrated effective background subtraction at high event rates.
• Improved polarization correlation visibility from 88.7% to 96.9% using the updated model.
• Successfully accommodated complex recovery behavior in detectors.

Conclusions:

• The proposed method enhances accuracy in coincidence measurements under detector saturation.
• This technique is valuable for applications requiring high signal-to-noise ratios with photon detectors.
• The method offers improved performance in scenarios with rapid flux changes.