Investigating MIMO technology in free space optical communication systems for evaluating performance across various environment parameters

• Advanced technology for next generation s free space optical communication. • License free and very fast Communication • Comparison of different models SISO,16 × 16 MIMO, 32 × 32 MIMO • Method MIMO-SPATIAL DIVERISTY with Double boosted optical amplifiers • Simulation done by using Opti-system software Free-space optical communication (FSOC) has gained approval for its ability to transmit large amounts of information over a reasonable range without requiring an optical fibre structure. Despite the recent disagreement on constrained capability, it has emerged as the most optimal option for the optical communications domain. Because environmental factors have a huge effect on the capacity and availability of free-space optical (FSO) links, especially when adverse weather lowers the signal strength and visibility range, this study looks at what happens to the FSO link when the atmosphere is turbulent in different ways. This case study comprehensively examines how weather conditions reduce signal strength. When we look at the visible spectrum, Q-factor, and BER, we can see that the implied MIMO with the spatial diversity-MRC technique and double-boosted optical amplifier is much better than the previous simulation-based work. We use advanced techniques, such as MIMO technology for double-boosted amplifiers and the Bessel optical filter, to create a model that outperforms previous methods in terms of the quality factor and BER.The proposed system demonstrates exceptional performance, achieving a Q-factor of 72.29 under heavy rain and 58.31 under dense fog, surpassing previous models by 15–20%. Additionally, the bit error rate (BER) was maintained at near-zero levels across all weather conditions, with the only exception being severe snow, where the BER reached 4.22 e − 18 , highlighting the system's robustness and reliability.