The Simulation Of Aberration Effects To The Scintillation Characteristics Of Laser Propagation In Atmosphere

The turbulence and defects of optical system are two key factors that distorting the wave front of the laser propagation in atmosphere.We studied the scintillation characteristics of the focused Gaussian laser beam which effected by single and compound aberrations propagating in the Kolmogorov power spectral distribution fitted atmosphere based on multi-phase screen numerical simulation method.(1)Established a model to simulate the non-ideally focused Gaussian laser propagation in atmosphere,which the wave front is modulated by single and compound aberrations that are generated according to the decomposition method of Zernike polynomials.(2)The numerical simulation to the scintillation effects of a Gaussian laser beam with different single aberration propagating in atmosphere is performed.obtained the effect characteristics of typical aberrations to the scintillation of non-ideally laser beam.The results show that the aberration of Z3?Z7 and Z4?Z8?Z11?Z13?Z24 will promotes and delays the appearance of axis-scintillation saturation respectively when the weight of Z3 aberration is lower than 0.15 while others are lower than 0.3.All single aberrations will retards or even eliminates the decline trend of the axis-scintillation after the scintillation saturation.The Z7 aberration is a disadvantage to the free atmospheric laser communication because of the strongest promotion to the axis-scintillation.The energy diffusion of the laser beam and the standard deviation of ln(I/I0)both are positively correlated with the strength of turbulence and the weight of each aberration,excepting for the standard deviation of ln(I/I0)for Z7 aberration,and the standard deviation of ln(I/I0)will be reaches a stable peak before the scintillation saturation.In most cases,the skewness of the probability density distribution of ln(I)is less than zero while its kurtosis is greater than zero,and with the strength of turbulence increases,the light intensity is closer to the log-normal distribution.(3)The numerical simulation was also performed on the case of compound aberrations,and the results indicate that the axis-scintillation changes with the strength of turbulence is not obvious under different compound aberrations in weak turbulence,but the variation is significant in moderate and strong turbulence conditions with different compound aberrations,and the value of the axis-scintillation are all lower than those without the additional system aberration.Compound aberrations will also retarding the decline trend of the axis-scintillation after the axis-scintillation saturation,and the skewness of the probability density distribution of ln(I)is less than zero while its kurtosis is greater than zero too.In general,the effect of compound aberrations on the light intensity distribution is not obvious.