Noise and Breakdown Characterization of SPAD Detectors with Time-Gated Photon-Counting Operation

Area of Science:

• Photonics and Semiconductor Devices
• Integrated Circuit Design

Background:

• Time-gated single-photon avalanche diodes (SPADs) are crucial for low-noise photon counting.
• Accurate characterization of SPAD noise and performance is essential to prevent lengthy experimental iterations.

Purpose of the Study:

• To conduct an extensive empirical study of breakdown voltage, dark-count, and afterpulsing noise in a 0.35-μm CMOS time-gated SPAD.
• To introduce an effective SPAD breakdown voltage for efficient noise modeling.

Main Methods:

• Experimental data acquisition under dark conditions.
• Analysis of breakdown voltage, dark-count, and afterpulsing probabilities.
• Development of noise models based on excess bias voltage and gating duration.

Main Results:

• An "effective" SPAD breakdown voltage was introduced for modeling.
• Dark-count and afterpulsing probabilities were characterized concerning excess bias and gating time.
• The study demonstrated how SPAD noise impacts speed and sensitivity trade-offs.

Conclusions:

• The presented breakdown and noise models facilitate accurate SPAD detector design and optimization.
• Understanding SPAD noise mechanisms is critical for balancing speed and sensitivity in detector applications.