Propagation Of Truncated Laguerre Gaussian Beam In Non-kolmogorov Turbulence

The invention of laser has greatly promoted the development of human science andtechnology. Laser characteristics of monochromaticity is good, good coherence, gooddirectivity, high brightness, which has played a irreplaceable role in information, scientificresearch, medical, industrial, commercial, military and other fields. In communicationtechnology, laser atmospheric communication is limited by attenuation and turbulence thatcased by the earth’s atmosphere. Previous studies are mostly based on Kolmogorov turbulencemodel, and there is a big error with the experimental values while the beam propagating alongthe vertical direction in turbulent particularly stable. Non-Kolmogorov model can match theatmospheric turbulence well in the troposphere and the stratosphere, and it has attracted manyscholars’ attention. This paper has studied the propagation of truncated Laguerre-Gaussianbeam by use the non-Kolmogorov turbulence model.The first chapter introduces our writing purpose of this paper, and it also contains thedevelopment and research status of beam propagating in atmosphere. The second chapterintroduces the composition of the atmosphere and the influence on the beam propagation,scattering, absorption, beam drift, spread and scintillation are included. It mainly introducesthe theory of turbulence models, including their applicable conditions and relationships Thethird chapter introduces the complex Gauss superposition method that proposed by Wen et al,and studies the propagation of truncated Laguerre Gaussian beam in non-Kolmogorovturbulence. The main content is:1) TheM2factor of truncated standard Laguerre Gauss beam in non-Kolmogorovturbulence has been calculated by using the generalized Huygens Fresnel principle and thegeneralized two moment theory combining with the hard edge aperture approximation, and itanalyzes the impact of wavelength, beam order, truncation parameter and turbulent parameteron theM2factor.2) Based on the generalized Huygens Fresnel principle and transformation relationshipbetween Hermite Gaussian and Laguerre Gaussian, the intensity and rms beam widthexpressions of truncated elegant Laguerre Gaussian beam in non-Kolmogorov turbulence hasbeen deduced. We have studied the influence of truncated parameter, beam order, inner andouter scale of turbulence on intensity and beam width, which have some reference value.