Scintillation properties of a truncated flat-topped beam in a weakly turbulent atmosphere

We derive an explicit expression for the scintillation index of a truncated flat-topped (FT) beam in a weakly turbulent atmosphere. Under suitable conditions, the derived formula reduces to the expression for the scintillation index of a FT beam or Gaussian beam without truncation. The scintillation properties of a truncated FT beam in a weakly turbulent atmosphere are illustrated numerically. It is found that the truncation parameter has strong influence on the scintillation properties, and the advantage of a FT beam over a Gaussian beam for reducing the negative influence of turbulence disappears gradually as the truncation parameter decreases.

► Analytical formula is derived for the scintillation index of a truncated flat-topped beam in turbulent atmosphere.
► The scintillation properties depend on the truncation parameter and the beam order.
► The advantage of a flat-topped beam over a Gaussian beam disappears gradually as the truncation parameter decreases.