1. Overview

Single Photon Counting Modules (SPCMs) are advanced optical sensors designed to detect individual photons with high temporal and spatial resolution. Based on solid-state photodetectors, these modules operate in Geiger mode to achieve single-photon sensitivity. Their ability to quantify ultralow light levels makes them critical components in quantum optics, biomedical imaging, and precision measurement systems.

2. Main Types and Functional Classification

3. Structure and Components

Typical SPCM architecture consists of: (1) Photon detection layer (silicon APD, superconducting nanowire); (2) Quenching circuitry (RC-active/passive); (3) Signal amplification stage; (4) Temperature stabilization module; (5) Digital output interface (TTL/USB). Advanced modules integrate time-to-digital converters for photon arrival time tagging.

4. Key Technical Specifications

5. Application Fields

• Quantum Communication: QKD systems (e.g., ID Quantique Clavis3)
• Biophotonics: Single-molecule fluorescence detection
• Environmental Monitoring: LIDAR systems for atmospheric particle analysis
• Industrial Metrology: Precision thickness measurement in semiconductor manufacturing

6. Leading Manufacturers and Products

7. Selection Recommendations

1. Match spectral response range to application wavelength
2. Balance PDE requirements with acceptable DCR levels
3. Consider cooling requirements for noise-sensitive applications
4. Evaluate timing resolution needs against system integration complexity

8. Industry Trends

Current developments focus on: (1) Increasing PDE beyond 90% through nanostructured surfaces; (2) Reducing dark counts to sub-Hz levels via cryogenic operation; (3) Developing CMOS-compatible single-photon imagers; (4) Integrating quantum dot photon number resolving capabilities. Market growth is driven by quantum computing infrastructure and autonomous vehicle LIDAR systems.