  One of the main problems faced by communication systems is the presence of
skip-zones in the targeted areas. With the deployment of the fifth-generation
mobile network, solutions are proposed to solve the signal loss due to
obstruction by buildings, mountains, and atmospheric or weather conditions.
Among these solutions, re-configurable intelligent surfaces (RIS), which are
newly proposed modules, may be exploited to reflect the incident signal in the
direction of dead zones, increase communication coverage, and make the channel
smarter and controllable. In this paper, we tackle the skip-zone problem in
near-terrestrial free-space optical (nT-FSO) systems using RIS. We carry out a
performance analysis of RIS-aided nT-FSO links affected by turbulence and
pointing errors, for both heterodyne detection (HD) and intensity
modulation-direct detection (IM/DD) techniques. Turbulence is modeled using the
Gamma-Gamma (G-G) distribution. We analyze the model and provide exact
closed-form expressions of the probability density function, cumulative
distribution function, and moment generating function of the end-to-end
signal-to-noise ratio, $\gamma$. Capitalizing on these statistics, we evaluate
the system performance through the outage probability, $ P_{out} $, ergodic
channel capacity, $\overline{C}$, and average bit-error-rate, $\overline{P}_b$,
for selected binary modulation schemes. Numerical results obtained for
different turbulence levels and pointing errors confirm that the HD technique
outperforms IM/DD even in RIS-aided nT-FSO systems. These results also show
that using a blue color offers better channel capacity and communication
performance compared to red and green colors.
