摘要
根据广义惠更斯一菲涅耳原理，推导出了部分相干贝塞尔高斯光束在非柯尔莫哥诺夫湍流中传输时平均光强和偏振度的解析表达式，研究了部分相干贝塞尔一高斯光束在非柯尔莫哥诺夫湍流模型下的光强分布特征和偏振度变化规律，同时分析了指数项、折射率结构常量、湍流内外尺度以及拓扑荷、光源相干性等对光束传输性质的影响．数值计算表明，随着传输距离的增加，部分相干贝塞尔高斯光束的光强会从空心分布逐渐演变为高斯分布，同时光束会有一定程度的展宽．而且，当指数项值越接近于3．1，折射率结构常量越大，外尺度越大或者内尺度越小时，光强分布的演变越为迅速，展宽现象也越明显；当拓扑荷越小或者相干长度越小时，光强分布的演变越迅速，但是二者对展宽现象的影响并不明显．另外，偏振度在近距离处会经历一段振荡及升降变化过程，当距离足够远时会趋于一个稳定值，且该值等于光源平面上的初始偏振度．偏振度变化的快慢程度受指数项、折射率结构常量、湍流内外尺度、拓扑荷和相干长度等因素的影响．
Based on the extended Huygens-Fresnel principle, analytical expressions for the average intensity and degree of polarization of partially coherent Bessel-Gaussian beams propagating in non Kolmogorov turbulence were devived. The intensity distribution feature and the variation pricinple of polarization degree were studied, and the etfects of the exponent parameter, structure constant, outer scale, inner scale, topological change and coherent length on the propagation properties were analyzed. The results show that the beam profile approaches to a Gaussian shape from a hollow shape and gets some spreads with increasing the value of the propagation distance. The average intensity distribution changes more quickly and gets more spreads with exponent parameter closer to 3. 1, larger structure constant, larger outer scale and smaller inner scale. When the topological charge or coherent length is smaller, the average intensity distribution changes faster, but it has few effects on the spread phenomenon. Furthermore, at near distance the degree of polarization first fluctuates, then a rise and a reduce appear in succession, and when the propagation distance is long enough it tends to a stable value which equals the initial value on the source plane. The variation process is affected by the exponent parameter, structure constant, outer scale, inner scale, topological charge and coherent length.
出处
《光子学报》
EI
CAS
CSCD
北大核心
2014年第1期1-6,共6页
Acta Photonica Sinica
基金
国家自然科学基金（No.61101005）和北京航空航天大学基本科研业务费（No.YwFB-D2-XX-2）资助
关键词
大气光学
部分相干贝塞尔高斯光束
非柯尔莫哥诺夫湍流
平均光强
偏振度
Atmospheric optics
Partially coherent Bessel-Gaussian beams
Non-Kolmogorov turbulence^Average intensity
Degree of polarization
