Free Space Optics (FSO) has the potential to offer fast broad-bandwidth communication, but experiences signal loss due to atmospheric attenuation. Our study assesses the performance of different lens configurations to mitigate the fog scattering loss in a low-cost visible-band FSO communication system. We built a fog-testing chamber and novel transmitter board to evaluate our FSO link at four different visible-band wavelengths and three different lens configurations. We also analyze the receiver signal strength to determine the fog-induced attenuation and compare each lens performance in the system. To design and evaluate the optimum lens system, several novel transmitterreceiver lens configurations are analyzed and compared: plano-convex to plano-convex (P-P), bi-convex to planoconvex (B-P), and bi-convex to bi-convex (B-B). We observe that the visible-band wavelength can minimizes the amount of fog-induced signal loss. The lens configuration in conjunction with the most optimal visible-band wavelength is then analyzed with various fog levels. We determine the most efficient double-lens configuration in the FSO system with fog-induced noise. On average, the biconvex-planoconvex system performed 63.85% better than the planoconvex-planoconvex system and 50.42% better than the biconvex-biconvex system. These results can be attributed to the spherical aberration from the transmitter lens and will be discussed in the paper.
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