## 1 Introduction  
With the advancement of society towards full automation and remote management systems, there is a significant demand for network systems capable of handling a large number of transceivers [1]. Primary attributes of fifth-generation and future communication systems consist of robust security protocols, ultra-low latency (as low as 0.1 milliseconds), and remarkably high data transfer capacities (up to 1 Terabit per second) [2; 3]. FSO technology is capable of providing very high data transmission rates, high security, and low latency compared to radio frequency (RF) technology, offering advantages in these aspects [4; 5]. Furthermore, FSO offers advantages such as unlicensed spectrum usage and low installation costs [3; 4]. These features make FSO an optimal technological solution for the imminent advent of fifth-generation and the subsequent sixth generation of wireless communication systems [6]. However, due to the nature of FSO as a line-of-sight (LoS) technology, it is highly susceptible to AT [7], PE [8], and other factors [9], which make long-distance communication challenging [3; 10]. Numerous methodologies have been developed to enhance FSO communication [7; 8; 9]. In recent times, RIS have emerged as a promising innovation in the research field. Their objective is to mitigate LOS limitations for FSO links through active control over the direction of reflected beams [11; 12]. RIS modules are passive components that operate autonomously without the need for a dedicated power source [13]. Since RIS only needs to reflect incident waves in the desired direction, there is no need for analog-to-digital/digital-to-analog converters or power amplifier circuits, thereby avoiding the impact of receiver noise [14; 15]. These advantages make RIS a cost-effective, easy-to-deploy, and energy-efficient relay that can be used in wireless RF and FSO communication systems [16; 17]. In [12], [PERSON] et al. investigated the use of intelligent reflecting surfaces to relax the LoS requirement of FSO systems. [PERSON] et al. in [8] implemented an RIS-assisted FSO system in a smart city scenario and studied the impact of signal blockage and Gamma-Gamma (G-G) turbulence on the system performance. In [18], [PERSON] et al. gave an analysis of RIS-Based Terrestrial-FSO Link Over G-G Turbulence With Distance and Jitter Ratios. In [19], [PERSON], [PERSON] et al. have presented a feasible multi-branch wireless optical communication setup utilizing optical reconfigurable intelligent surfaces. In [18; 20], the authors introduced a unified end-to-end Probability Density Function (PDF) expression for a terrestrial FSO RIS system considering the combined impact of G-G atmospheric turbulence, pointing error on the S-IRS/IRS-D links, pointing error ratios, and the placement of the RIS. In summary, RIS integration in FSO communication indeed offers several compelling advantages that directly address the mentioned challenges:  
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2. Mitigation of Atmospheric Transmission Losses: By leveraging RIS, we can manipulate the propagation path of signals, thereby reducing losses incurred due to atmospheric transmission [19]. RIS facilitates directing signals towards the intended receiver, effectively minimizing transmission distances and associated losses within the atmosphere [12]. 3. Compensation for Pointing Errors: RIS provides the capability to adjust phase and amplitude during signal propagation, offering compensation for pointing errors. Through the intelligent modulation capabilities of RIS, we can achieve more precise signal alignment, thus enhancing system stability and performance [18; 20]. However, FSO systems are mainly vulnerable to malicious jamming signals due to three key factors. (1) In FSO communications, the selection of operational wavelengths is very limited. Some operational wavelengths for FSO transmission include 830 nm, 1300 nm, and 1550 nm [21]. Considering eye safety and lower optical losses, 1550 nm is the most commonly used operational wavelength in many FSO-based applications [21].