Generating phase screens to replace phase fluctuation caused by atmospheric turbulence is essential for simulation of light propagation through the atmosphere.
Error between power spectral density of actual turbulence and traditional Kolmogorov model illustrates the importance of generating non-Kolmogorov phase screen.
Meanwhile, methods used to generate phase screen at present show different kinds of disadvantages respectively.
In this paper, a research team led by Prof. Dr. SU Xiuqin from Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences (CAS) adopts a new method named “intrinsic embedding fractional Brownian motion (IE-FBM)”.
Phase screens generated by different methods. (Image by XIOPM)
First, relationship between phase screen and FBM is analyzed. Next, principle of IE-FBM is clarified. They expand the correlation matrix and generate a stationary Gaussian surface through two fast Fourier transforms, which is the principle of intrinsic embedding. After that, they adjust the Gaussian surface into an FBM surface. Finally, simulation results demonstrate that IE-FBM combines advantages of traditional methods.
Phase structure function becomes closer to theoretical value no matter how we set parameters of phase screen. Besides, both low and high frequency components of phase screen are sufficient and creases don’t exist. In addition, time consumption reduces apparently.
In conclusion, the method is comprehensively optimal choice to generate phase screen.
(Original research article “Optik - International Journal for Light and Electron Optics” (2020) https://doi.org/10.1016/j.ijleo.2020.164444)
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