Research On Laser Signal Temporal Spreading In The Slant Path Through The Atmospheric Turbulence

Since the 21 st century, the entire society has entered the Information Age under the urgent need of the global economy. Amount of information appears explosive growth trend, and communication technology develops fast toward the big data, high-speed and diversified. The free space optical communication technology is considered to be is expected to surpass the traditional microwave communication, which is the effective means to break through the bottleneck of signal transmission speed. Since the 1990 s, the research work of the free space optical communication system has been far developed from the experimental research to the application of the industry.In the free space optical communication system, the laser as the carrier of the signal will be affected by the atmosphere in the atmospheric channel. The pulse broadening effect of the laser signal can reduce the theoretical capacity of the atmospheric channel, which leads to the increase of the communication rate of the system. So the study of the effect of atmospheric channel about the time domain broadening of optical pulse is very important to improve the performance of space optical communication system.This paper mainly according to the link in the slant path atmospheric turbulence on the laser pulse broadening in the time domain of theoretical analysis and Monte Carlo simulation study, my work mainly includes the following aspects:1.Based on typical atmospheric turbulence model and the modified von Karman turbulence spectrum simplified theoretical model,the theoretical analysis of the broadened time domain caused by the pulse broadening and initial pulse half width under the daytime and nighttime atmospheric turbulence, transmission distance and zenith angle factors.We give the optimization scheme about the improved laser pulse broadening caused by the atmospheric turbulence at the last.2.Based on the principle of geometrical optics and turbulence bubble model,we establish the Carlo Monte simulation model about the time-domain broadening of the laser pulse caused by the atmospheric turbulence at the horizontal link.Based on this model, we analyze the effect of standard deviation of atmospheric turbulence outside the atmospheric turbulence and atmospheric refractive index fluctuation on the results of Carlo Monte.3.Based on level atmospheric turbulence Monte Carlo simulation model we establish the Monte Carlo simulation model at the slant link, simulate pulsed light signal link Gauss broadening effect under the intensity modulation process, and analysis of the atmospheric transmission distance, initial pulse half width and receive port diameter and other parameters of laser signal time domain broadening effects.