Hollowness impact on turbulence mitigation in Hollow Gaussian beam-based long free-space optical communication links

Abstract The propagation properties and scintillation indices of a Hollow Gaussian beam (HGB) propagating in a free-space optical (FSO) communication link are investigated. The impact of the system parameters such as wavelength, beam waist and beam orders on the beam size, Kurtosis parameter, scintillation and received intensity are examined. It is found that beam profiles with higher beam waists expand less as propagate. Besides that, Hollow Gaussian beams (HGBs) tend to have a Gaussian-like profile as propagate for longer distances. Further, the size of HGBs expands for higher beam orders. Also, operating at a higher wavelength yields to higher beam size. Moreover, a rapid increase is observed in the Kurtosis parameters of beams with bigger beam waists. Finally, HGBs with small beam waists have the advantage to reduce the scintillation level. Here, HGBs with small beam waists have scintillation levels less than Gaussian beam. Accordingly, the presented results will contribute significantly to the design and improvement of FSO communication systems in a wide range of applications.