Abstract:In this paper, based on the eavesdropping model of eavesdroppers near legitimate users, the effect of atmospheric channel correlation on the physical layer security of free-space optical link is analyzed. According to the joint probability density function and cumulative distribution function of gamma-gamma distribution, a new closed-form expression of intercep-tion probability is derived. Numerical results show that the interception probability of free-space optical system depends on turbulence intensity, channel correlation and radial displacement attenuation of eavesdroppers.