Abstract
In this paper, a novel analytical expression for the temporal pulse broadening caused by atmospheric dispersion and weak turbulence is derived. We developed an on-axis two-frequency mutual coherence function (MCF) for dispersive pulse propagating in weak atmospheric turbulence. Based on the derived temporal pulse broadening expression we formulated the signal-to-noise ratio (SNR) for Gaussian pulse propagating along a horizontal path, and we deducted an analytical expression for the bit error rate (BER) caused by dispersion and weak atmospheric turbulence effect on terrestrial free-space optical transmission system. Specific examples are presented for the pulse broadening due to weak turbulence and atmospheric dispersion. The results show that the temporal pulse broadening increases with propagation distance and decreases with low outer scale turbulence. The analytical BER results validated by using Monte Carlo simulations for on-off keying (OOK) intensity modulation/direct detection (IM/DD) show that BER due to pulse broadening is very significant when the propagation distance is increased. However, longer propagation distance with minimum bit error rate can be achieved by increasing the input power.