Next-generation 4 × 4 × 10 Gbps FSO network with polarization-integrated Laguerre/Hermite–Gaussian modes

A new method for addressing the increasing needs for bandwidth is mode division multiplexing (MDM). Its use in spatial modes for free-space optical (FSO) communication has produced encouraging outcomes. In order to increase data capacity, this study examines an MDM-FSO system that makes use of Hermite–Gaussian and Laguerre–Gaussian modes, namely HG[0, 0], HG[0, 1], LG[0, 0], and LG[0, 1]. Polarization multiplexing is also taken into consideration to enhance performance even more. According to simulation results, the HG[0, 1] mode allows for a maximum link range of 380–570 m in a variety of weather scenarios, including light fog, rain, mist, dry snow, and weak turbulence. It is noteworthy that the LG[0, 0] mode outperforms LG[0, 1] and HG[0, 1] at 160 Gbps data speeds. Under the gamma–gamma channel model, the system maintains a maximum spot size of 5–10.7 µm under various environmental circumstances. Additionally, it can accommodate a maximum divergence angle of less than 0.5 mrad in strong turbulence and 3 mrad in weak turbulence. The suggested MDM-FSO design is a viable contender for next-generation optical wireless communication systems because to its improved spectrum efficiency, high-speed data transmission, and increased capacity when compared to current FSO systems.