Modeling and performance investigation of 4 × 20 Gbps underwater optical wireless communication link incorporating space division multiplexing of Hermite Gaussian modes

In this work, we report the development of long-haul high-speed underwater optical wireless communication (UOWC) transmission link by incorporating space division multiplexing (SDM) of distinct Hermite Gaussian (HG) modes for enhanced channel-capacity. Four distinct 20 Gbps non-return to zero encoded information signals are transmitted over distinct HG modes of a single wavelength laser at 1800 m underwater link range to realize an 80 Gbps UOWC system. Also, we investigate the performance of the proposed UOWC transmission link under the influence of different operating wavelengths, aperture diameter, attenuation coefficient, and link range. Further, we optimize the proposed UOWC link performance in terms of spatial aperture to stabilize the bit-error rate (BER) performance of the link at high signal attenuation values and varying transmission link reach.