The Effects Of Turbulent Atmosphere On Laser Beam Propagation

This thesis emphasizes on the research of the theory and experiments of the laser beam propagation in the atmosphere, which are of great importance in the areas of laser radar, laser missile-guidance and communication . Since the effects of turbulent atmosphere is prominent, this thesis concentrates on the effects of the turbulent atmosphere on the laser beam propagation in the atmosphere .The atmosphere refractive index model, especially refractive index fluctuation, power spectrum, phase spatial structure constant are introduced in the following and the specific structure function is achieved. According to the Markov approximation under a long haul condition, we get the inter-correlation function, log-amplitude and phase covariance function .The thesis puts much emphasis on three phenomenon of the laser under the effects of turbulence, i.e., intensity fluctuation (atmosphere glistening) ,beam floating and extension, phase fluctuation. The thesis also discusses the thermal blooming and physical of the heat halo produced by intense laser. The thesis emphasizes on OTF and PSF of atmospheric turbulence. Taking three screen systems as the example, we get the ideal approximation model, especially the short-exposure OTF. Here the speckle pattern interference measuring theory is applied for the first time and the testing experiment is designed .We also tentatively propose a scheme to carry out the Fourier analysis and deconvolution solution process with computer, in order to achieve the aim of real-time model recognition by the speckle pattern interference measurement.