Exploring Challenges in Modern High Speed Free Space Optical Communication

Free-Space Optical (FSO) systems have gained significant importance in the field of due to their unique attributes. They provide a wide spectrum, increased bandwidth, high data rates, lightweight design, lower power consumption, and rapid deployment capabilities. FSO systems are especially advantageous for disaster recovery, defense purposes, addressing connectivity challenges in remote areas, and remote sensing. However, despite their many benefits, the effectiveness of FSO systems is impacted by challenges like beam deviation, spread, scattering, atmospheric turbulence, and alignment inaccuracies. These hurdles result in notable fluctuations in both Bit Error Rate (BER) and Signal-to-Noise Ratio (SNR), making the communication link impractical. To enhance the performance of FSO communication systems, this study delves into various channel models, modulation methods, and strategies to counter atmospheric disturbances such as turbulence, fog, absorption, and scintillation. The research discusses diverse modulation and diversity techniques in the. Additionally, it presents a comparative examination of SNR and BER influenced by various atmospheric factors affecting FSO systems. The primary goal of this survey is to offer an in-depth guide for developing cost-effective, high-capacity FSO connections.