Spot dancing of the laser beam propagated through the turbulent atmosphere.

The problem of spot dancing of the laser beam has attracted theoretical and experimental attention in recent years as one of the important problems in an optical communication system through the atmosphere. An analysis of this problem is made by using the Kolmogorov structure function of the refractive index and geometrical optics. Laser propagation experiments are carried out over 480-m and 1380-m paths. The standard deviations of spot dancing are measured by two methods, and the magnitudes of the structure constant Cn(2) are measured at the same time. The theoretical value of the spot dancing shows a satisfactory agreement with the experimental value. In addition, measurements of the fluctuations of spot dancing reveal that the power spectra show an inverse frequency characteristic over the frequency range of about 0.03-10 Hz.