Dead-time effect on SPAD detection efficiency

Area of Science:

• Photon detection
• Quantum optics
• Semiconductor devices

Background:

• Geiger-mode single-photon detectors offer low-light detection capabilities.
• Detector dead-time inherently limits the detection rate and overall efficiency.

Purpose of the Study:

• To investigate the impact of dead-time duration on the effective efficiency of single-photon avalanche-diode detectors.
• To compare simulation results with experimental data for validation.
• To analyze the dead-time dependence in both free-running and gated detection modes.

Main Methods:

• Experimental measurements of single-photon avalanche-diode detector performance.
• Monte Carlo simulations to model detector behavior.
• Derivation of analytical expressions to describe dead-time effects.

Main Results:

• Effective efficiency is demonstrably sensitive to detector dead-time length.
• Significant differences in dead-time dependence observed between free-running and gated modes.
• Gated mode generally shows superior efficiency, with potential improvements at extended dead-times.
• Free-running mode can rival gated mode efficiency under high background and long dead-time conditions.

Conclusions:

• Dead-time is a critical parameter influencing single-photon detector efficiency.
• Operational mode (free-running vs. gated) significantly alters the dead-time's impact.
• Gated mode offers advantages, but free-running mode provides signal timing independence, which can be beneficial.