This work presents the study of a free space optics (FSO) system that combines two multiplexing techniques: polarization division multiplexing (PDM) and mode division multiplexing (MDM). Four Hermite Gaussian (HG) modes are employed in two polarization states to transmit data from eight different users. The performance analysis is conducted under various rain and fog conditions to evaluate the system’s robustness. Furthermore, the system performance is compared with that of an MDM multiplexing system. The bit error rate (BER) and eye diagram are used as the main performance evaluation metrics in this analysis.

free space optics, mode division multiplexing, polarization division mutiplexing, Hermite gaussian multiplexing