Impact of Severe Desert Dust on Multi-Wavelength Free-Space Optical Links: A Comparative Study at 850, 1550, and 3800 nm

Free-Space Optical (FSO) communication offers high-bandwidth and safe links but suffers severe performance degradation in harsh atmospheric conditions, particularly in power-constrained systems operating through desert dust storms. This study presents a comprehensive MATLAB-based simulation to evaluate FSO link performance at wavelengths of 850 nm, 1550 nm, and 3.8 m over a 1 km link under extreme desert dust conditions, with a peak aerosol concentration of approximately 20,000 g/m³. The model incorporates realistic desert sand particle size distributions (median diameter 2.5 m, geometric standard deviation 2.0), Mie scattering theory, and non-spherical particle approximations. Key performance metrics, including received power, signal-to-noise ratio (SNR), bit error rate (BER), and outage probability, are analyzed. Simulation results show that all links experienced outage during the 300.5 s dust event due to received power falling below the receiver sensitivity threshold of − 35 dBm. Peak aerosol attenuation was similar across wavelengths, measuring 0.64 dB (850 nm), 0.65 dB (1550 nm), and 0.67 dB (3.8 m). The minimum received power reached − 38.49 dBm for the 3.8 m link. Performance was primarily limited by noise, with the Mid-Wave Infrared (MWIR) link exhibiting the poorest performance due to high detector noise (NEP = 5 pW/√Hz), resulting in a minimum SNR of 0.57 dB and a peak BER of 0.395. In contrast, the 1550 nm link achieved a minimum SNR of 1.32 dB and a peak BER of 0.230. These findings demonstrate that, under severe dust conditions, detector noise and particle characteristics can negate the expected advantages of longer wavelengths, highlighting the need for improved detector technology and robust link margins in dust-prone environments.