Scintillation reduction by multiple phase-locked beams with different polarization angles

A new approach is presented to reduce turbulence-induced scintillation by use of a phase-locked beams array composed of linearly polarized beams with different polarization angles. The noninterference of orthogonal polarizations suggests that the beams array mentioned above can act effectively as a two-mode partially coherent beam, and the percentage of a single mode is controllable by changing the polarization angles of the beams. Numerical calculation using a multiple-phase screen method is performed to analyze the on-axis scintillation index σ I 2 and mean received intensity 〈I〉 for the beams array propagating through weak, moderate, and strong turbulence. The effects of different polarization angles on σ I 2 and 〈I〉 at the receiver are studied. When the turbulence is weak, numerical calculations show that both σ I 2 and 〈I〉 are closely related to the polarization angles of the beams. And there will be a smaller scintillation index for a phase-locked beams array comprising beams with different polarization angles as compared to a uniformly polarized beams array. As the beams are phase-locked, the mean received intensity provided by them is larger than that provided by an incoherent beams array. For it is quite easy to change the polarization angles, phase-locked beams array comprising beams with different polarization angles can be a promising source in the applications that need a balance between scintillation and mean received intensity in weak turbulence conditions. When the turbulence is moderately strong, incoherent beams array is actually a better choice, because the scintillation index is smaller and the mean received intensity is as much, compared to a phase-locked beams array.