Target Acquisition for Collimation System of Wireless Quantum Communication Networks in Low Visibility

Area of Science:

• Optics and Photonics
• Wireless Communication Networks
• Quantum Technology

Background:

• Severe low-visibility environments, such as those filled with smoke, degrade the performance of near-infrared (NIR) collimation systems in quantum drone communication networks.
• Smoke-scattering noise presents as a steeply varying medium-high-frequency modulation, challenging target detection.

Purpose of the Study:

• To propose an improved dual-threshold method for target acquisition in severe low-visibility environments.
• To leverage long-wave infrared (LWIR) quantum cascade lasers (QCLs) to overcome the limitations of NIR systems.

Main Methods:

• Developed an improved dual-threshold method incorporating trend line analysis for LWIR QCLs.
• Simulated smoke-scattering noise characteristics and their impact on target detection.
• Evaluated the method's performance under varying signal-to-noise ratios (SNRs) and intensity variations.

Main Results:

• LWIR lasers demonstrate an advantage over NIR lasers in distinguishing target information from smoke noise for particle sizes < 4 μm.
• The proposed method achieves good target acquisition with conventional thresholds (0.7 peak intensity, 0.8 peak rising velocity) at high SNRs.
• Adaptive threshold resetting (0.6 peak intensity, 0.6 peak rising velocity) enables good target acquisition even at low SNRs and steep intensity variations.

Conclusions:

• The improved dual-threshold method effectively enhances target acquisition in challenging low-visibility, smoke-filled environments.
• LWIR QCLs offer superior performance compared to NIR systems for quantum communication networks in such conditions.
• This research provides a valuable reference for refining collimation systems in wireless quantum communication networks operating in low visibility.