Research On The Simulation System Of Indoor Atmospheric Turbulence

When we use the telescope to observe the celestial bodies on the surface of the earth,the astronomical images of the astronomical telescope are blurred due to the random disturbance of the light transmission medium due to the presence of atmospheric turbulence.The emergence of adaptive optics has greatly improved the shortcomings of the ground telescope imaging.The simulation of atmospheric turbulence is an indispensable part of the development of adaptive optics,so it is of great theoretical and practical significance to simulate the atmospheric turbulence.Numerical simulation of atmospheric turbulence has many advantages such as controllability,repeatability and low cost for indoor test adaptive optical system.In this paper,we have a detailed analysis of the Zernike polynomial method and the power spectrum inversion method.On this basis,we propose a non-uniform sampling method to simulate the atmospheric turbulence phase screen by the power spectrum inversion method.The phase screen obtained by the inversion of the atmospheric turbulence algorithm under the non-uniform sampling power spectrum has a high quality,but the phase screen cannot be generated by the fast Fourier transform under the non-uniform sampling method.To solve this problem,this paper proposes the use of GPU technology and NUFFT algorithm to accelerate the turbulence phase screen simulation.The simulation results show that the GPU technology and the NUFFT algorithm have a high acceleration effect on the turbulence phase screen simulation,which saves a lot of time for the numerical simulation of the turbulence phase screen.After the turbulence phase screen data is generated,it is also necessary to solve how to construct the optical transmission link to realize the modulation of the beam.In order to solve this problem,pure phase liquid crystal spatial light modulator(LC_SLM)is used as turbulence simulation device.We use the turbulence phase screen as a control signal to load into the liquid crystal spatial light modulator,to achieve the establishment of the atmospheric transmission link for the adaptive optical system to provide the conditions for indoor testing.On this basis,we integrate the generation module of the turbulent phase screen with the signal loading module and add the display module to realize the development of the numerical simulation control platform for atmospheric turbulence.And,we have done a lot of optimization and art on the control platform,so that the control platform with high efficiency and stability of the work performance.