WDM Transmission for Free Space Optics under Different Atmospheric Conditions

Abstract

Abstract

This paper presents the design and simulation of a 32-channel WDM transmission system for free space optics (FSO) taking different atmospheric effects (rain, fog and scintillation) into account. The commercial software, namely, OptiSystem is used for the design of WDM-FSO where the system performances are evaluated in terms of bit error rate (BER) and eye diagrams. Weather data of Khulna, a district in the south-western part of Bangladesh, is used to calculate the FSO channel attenuation due to rain while the attenuations due to fog and scintillation are adopted from literature. Simulation results show that 32-channel WDM-FSO link can reach up to 3.2 km under rainy weather conditions with input power and transmission speed of 10 dBm and 2.5 Gbps respectively for each channel. The maximum link distances are found to be 95 m  and 950 m for the atmospheric attenuation due to dense fog and high turbulence respectively.

Keywords: Free space optics, wavelength division multiplexing, bit error rate, eye diagram, optical communication