超短脉冲大气传输展宽及脉冲波形分析

Analysis of Ultrashort Pulse Waveform and Broadening Caused by Atmospheric Turbulence and Dispersion

激光通信技术是实现高效通信的重要手段。大气激光通信链路中,大气的散射、吸收和湍流严重制约激光传输质量。分析了激光通信系统中由于大气湍流和色散造成的脉宽展宽,计算了脉宽展宽量与湍流大气折射率结构常数、初始脉宽和传输距离之间的关系;比较了不同发射激光脉宽、不同发射能量下的脉冲波形特性。数值计算及仿真结果表明,激光脉宽随传输距离、大气湍流的增大而增大,长脉宽的超短脉冲激光受大气湍流和色散的影响小,并且脉宽增大,激光功率降低,研究结论对超短脉冲的应用具有一定的意义。

Laser communication technology is an important mean for achieving effective signal transmission. However,the quality of laser beam was constrained by atmospheric scattering,absorption and turbulence seriously.The turbulence-induced and scattering-induced pulse width broadening in laser link was analyzed.The variations of pulse width broadening with the index of refraction structure constant,input pulse width,and propagation distance were calculated.The characteristics of laser waveform with different original pulse width and emission energies were compared. The simulation results show that the width of laser increases correspondingly when the propagation distance or the index increases.It means that laser with large pulse width is affected by atmosphere weakly,meanwhile,the power of laser decreases when the pulse width broadening appeares.The conclusion has certain significance to the applications of ultrashort pulse.