Influence of non-Kolmogorov atmospheric turbulence on the spectral changes of rectangular array beams

•The spectral changes of beams in non-Kolmogorov turbulence have been studied.•There exist spectral shifts and spectral transitions for superposed beams.•The spectral changes depend on the non-Kolmogorov model parameters.

Based on the non-Kolmogorov spectrum, using the extended Huygens–Fresnel principle, the analytical expressions for the spectrum of the coherent and incoherent superpositions of rectangular array Gaussian Schell-model (RAGSM) beams propagating through non-Kolmogorov atmospheric turbulence are derived, and are used to study the influence of non-Kolmogorov atmospheric turbulence on spectral changes of coherent and incoherent superpositions RAGSM beams. It is shown that, with the increment of the general exponent α and the inner scale of turbulence l0, as well as the decrement of the general structure constant C˜n2, the magnitude of the spectral shift will increase, the magnitude of spectral transition will decrease and the critical position of spectral transition will decrease. The outer scale of turbulence L0 has little effect on the spectral shift and spectral transition.