啁啾脉冲高斯光束在大气湍流中的传输特性

Spectral characteristics of chirped pulsed Gaussian beams propagating in turbulent atmosphere

基于广义惠更斯-菲涅耳原理,推导出啁啾脉冲高斯光束在湍流大气中传输的光谱解析表达式,并对解析表达式进行了数值仿真。结果表明:啁啾参数越大,光源谱宽越宽;当光源相对谱宽大于0.336时,轴上点光谱产生蓝移;湍流使得轴上点光谱的相对频移量减小,相对频移量随源光谱宽的增大而非线性增大;增大光束束腰半径可减小湍流对光谱频移、光束展宽的影响。

Based on the extended Huygens-Fresnel principle,analytical expressions are derived for the cross-spectral density matrix of chirped pulsed Gaussian beams propagating in turbulent atmosphere,which are then numerically simulated.It is shown that there are blue shifts in the spectra of axis point when the spectral width of chirped pulsed Gaussian beams is more than a certain value of 0.336.The turbulence induces the decrease of relative frequency shift of on-axis spectra;the relative frequency shift of on-axis spectra increases nonlinearly with the increasing light source spectral width.Increasing the beam waist radius can inhibit the relative frequency shift and the beam broadening.