Systematic afterpulsing-estimation algorithms for gated avalanche photodiodes.

Area of Science:

• Photonics and Optoelectronics
• Semiconductor Devices
• Signal Processing

Background:

• Indium Gallium Arsenide (InGaAs) avalanche photodiodes (APDs) are crucial for optical detection.
• Afterpulsing is a significant noise mechanism in gated-mode APDs, limiting performance.
• Accurate signal extraction is essential for reliable optical measurements.

Purpose of the Study:

• To develop a method for efficiently extracting optical signals from InGaAs APDs in gated mode.
• To enable the estimation of signal counts versus noise counts, specifically afterpulsing.
• To allow high detection efficiency and full bandwidth operation of InGaAs APDs.

Main Methods:

• A novel signal extraction method for InGaAs APDs operated in gated mode.
• Estimation of the true signal fraction by differentiating from afterpulsing noise.
• Development of algorithms for real-time or post-processing applications.

Main Results:

• The method effectively separates optical signals from afterpulsing noise, even when noise dominates.
• It allows InGaAs APDs to operate at high detection efficiencies and full bandwidth.
• The technique is applicable even in configurations with orders of magnitude more afterpulsing than signal.

Conclusions:

• The proposed method significantly improves the performance of InGaAs APDs by mitigating afterpulsing effects.
• It offers a versatile solution for optical signal extraction in challenging noise conditions.
• These algorithms can complement existing afterpulsing reduction technologies.