Scintillation index of flat-topped Gaussian beams

Abstract

The scintillation index is formulated for a flat-topped Gaussian beam source in atmospheric turbulence. The variations of the on-axis scintillations at the receiver plane are evaluated versus the link length, the size of the flat-topped Gaussian source, and the wavelength at selected flatness scales. The existing source model that represents the flat-topped Gaussian source as the superposition of Gaussian beams is employed. In the limiting case our solution correctly matches with the known Gaussian beam scintillation index. Our results show that for flat-topped Gaussian beams scintillation is larger than that of the single Gaussian beam scintillation when the source sizes are much smaller than the Fresnel zone. However, this trend is reversed and scintillations become smaller than the Gaussian beam scintillations for flat-topped sources with sizes much larger than the Fresnel zone.

Relay propagation of partially coherent flattened Gaussian beam in turbulent atmosphere

“…(3) r 0 is the spatial correlation length and v ¼ x; y. With the help of Huygens-Fresnel diffraction integral [4,5,14] the cross-spectral density at relay system can be expressed as…”

“…Average intensity distribution and scintillation of various laser beams propagating in turbulent atmosphere have been studied widely [4][5][6][7][8][9][10]. Relay propagation is affected not only by turbulent atmosphere but also by the limitation and the aberration of the receiving beam of relay system.…”

Scintillation Index of a Gaussian Schell-Model Beam on Slant Atmospheric Turbulence

“…Many researchers started to study the propagation characteristics of different types of sources in turbulence [23,24]. Baykal and Eyyubogl [25] developed the scintillation index formula for a flat-topped Gaussian beam source on axis in turbulence. They found that using a flat-topped Gaussian beam in a FSO link will bring advantages in scintillations compared with Gaussian-beam incidence.…”

Intensity correlations of general type beam in weakly turbulent atmosphere

“…In some applications, especially in optical heterodyne detection, it is important to have an understanding of the intensity correlations at the receiver plane [1]. Recently, the effects in weak atmospheric turbulence of different types of optical incidences on the scintillations are reported for beams of sinusoidal Gaussian [2,3], annular [2,4] and flat-topped Gaussian [5][6][7]. Various aspects of intensity correlations are scrutinized by many researchers.…”