湍流大气中J0相关部分相干平顶光束的谱移

Spectral change of J0-correlated partially coherent fiat-topped beam in turbulent atmosphere

摘要: 为了研究相干度为零阶贝塞耳函数的部分相干平顶光束的光谱特性,采用广义惠更斯-菲涅耳公式推导了J0相关部分相干平顶光束通过湍流大气的光谱分布表达式,分析了大气折射率结构常数、平顶阶数、光源的中心频率、相干性参量以及谱宽对谱移的影响。结果表明,光源的中心频率、光谱宽度、空间相干参量、湍流强度对轴上谱移量影响较大;另外,随着湍流的增强,光谱位移量减小;在自由空间中,平顶光束的阶数越高,对谱移的影响就越大,但在湍流大气中阶数对谱移几乎没有影响。

Abstract: In order to study the spectral properties of J0-correlated partially coherent flat-topped beam in turbulent atmosphere,the analytical spectrum expression of J0-correlated partially coherent flat-topped beam was derived based on extended Huygens-Fresnel principle.The effect of structure constant,central frequency,spectrum width,coherence parameter and orders of flat-topped beams on the spectral shift was discussed.Results show that the above parameters have great effect on the value of the frequency shift.Furthermore,the spectral shift decreases with the increase of turbulence.In free space,the higher order of flat-top beam,the greater impact of the spectral shift,but the order has little effect on the spectral shift in turbulent atmosphere.