Experimental Investigation of the Effective Spectrum Bandwidth of the FSO Link with Scintillation

In free space optical (FSO) communications, the link performance is highly dependent on the atmospheric conditions including turbulence, which causes fluctuations in both the intensity and the phase of the received optical wavefront. In this paper, we experimentally investigate the FSO link considering the ambient temperature and the sun irradiation angle parameters. Furthermore, we investigate the scintillation effect on the FSO link in the frequency domain and present temporal spectra of the irradiance fluctuations. It is worth since it can be helpful to compensate the scintillation effect in a FSO link using adaptive optical alignment system. In addition, we show the measured effective spectrum bandwidth of fluctuations in moderate turbulence is less than 250 Hz for a 220 m link length, and evaluate the environmental effects on it under different turbulence conditions.