Infrared single-photon detector
Keywords:
Infrared single-photon detector
Product Overview
Single-photon detectors are instruments used for detecting weak signals at the single-photon level, playing an indispensable role in numerous fields such as quantum optics, biophotonics, and laser ranging. In recent years, single-photon detectors have been widely applied in the field of quantum cryptography and have become the core device for photoelectric conversion of quantum signals.
The WT-SPD series infrared single-photon detectors are low-cost, low-dark-count-rate, and highly stable optoelectronic instruments developed on the basis of research into quantum cryptographic communication systems. The device employs an InGaAs/InP single-photon avalanche diode as its photosensitive element. In addition to adopting a range of internationally recognized noise-reduction and afterpulse-suppression techniques—including gated operation and dead-time suppression—it also incorporates an original differential filtering scheme. This innovative approach not only maintains high detection efficiency but further reduces the dark count rate.
Product Parameters
● Dark count rate
The products are categorized into three models based on their dark count rates: Ultra-Low Noise (ULN), Low Noise (LN), and Standard (STD). The dark count rate requirements for each model under gate widths of 1 ns, 2 ns, and 3 ns are shown in the table below.
| Product Model | Effective door width | 10% | 15% | 20% | 25% |
| WT-SPD300-ULN | 1ns | <2.00×10 -6 | <4.00×10 -6 | <8.00×10 -6 | <2.00×10 -5 |
| 2ns | <5.00×10 -6 | <1.00×10 -5 | <2.00×10 -5 | <5.00×10 -5 | |
| 3ns | <1.50×10 -5 | <3.00×10 -5 | <6.00×10 -5 | <1.50×10 -4 | |
| WT-SPD300-LN | 1ns | <5.00×10 -6 | <1.00×10 -5 | <2.00×10 -5 | <5.00×10 -5 |
| 2ns | <1.25×10 -5 | <2.50×10 -5 | <5.00×10 -5 | <1.25×10 -4 | |
| 3ns | <3.75×10 -5 | <7.50×10 -5 | <1.50×10 -4 | <3.75×10 -4 | |
| WT-SPD300-STD | 1ns | <1.00×10 -5 | <2.00×10 -5 | <4.00×10 -5 | <1.00×10 -4 |
| 2ns | <2.50×10 -5 | <5.00×10 -5 | <1.00×10 -4 | <2.50×10 -4 | |
| 3ns | <7.50×10 -5 | <1.50×10 -4 | <3.00×10 -4 | <7.50×10 -4 |
● Detection efficiency
The detection efficiency is set in four levels: 10%, 15%, 20%, and 25%. The deviations between the actual detection efficiencies and the nominal values under different detector gate widths and operating temperatures are shown in the table below.
| Effective door width | Nominal efficiency ( % ) | Actual Efficiency ( % ) |
| 1ns | 20 | 20 ± 2 |
| 1ns | 25 | 25 ± 3 |
| 2ns | 10 | 10 ± 2 |
| 2ns | 15 | 15 ± 3 |
| 2ns | 20 | 20 ± 5 |
| 2ns | 25 | 25 ± 5 |
| 3ns | 10 | 10 ± 3 |
| 3ns | 15 | 15 ± 4 |
| 3ns | 20 | 20 ± 7 |
| 3ns | 25 | 25 ± 9 |
● Effective door width
| Door width (ns) | Detection efficiency (%) | Effective door width range (ns) |
| 1 | 10% | 0.1–0.4 |
| 20% | 0.2 to 0.6 | |
| 2 | 10% | 0.3–1.0 |
| 20% | 0.6–1.2 | |
| 3 | 10% | 0.8–2.1 |
| 20% | 1.0–2.5 |
● Post-pulse rate
The post-pulse rate is less than or equal to 3% (@100 MHz detector trigger frequency, 10 MHz laser trigger frequency, optical pulse duration of 50 ps, 0.1 photon per pulse, 1 ns detection gate width, 10% detection efficiency, and a dead time greater than or equal to 100 ns).
Scope of application
● Quantum Cryptographic Communication
● Quantum optics, biophotonics
● Laser rangefinding
● Atmospheric and water environment monitoring
● Fluorescence Lifetime and Fluorescence Spectroscopy
● Time-resolved single-molecule spectroscopy
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Landline: +86-551-63637001
Tel: +86-13514953141
Address: No. 2800, Innovation Avenue, High-Tech Zone, Hefei City, Anhui Province, Innovation Industrial Park Phase II, E2-901/902
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