近海面大气湍流中准直光束漂移特征的实验研究

Experimental Study on Beam Wander of Collimated Beam in Atmospheric Turbulence Under Sea Surface Environment

光斑漂移是光束在湍流大气中传输时的一个重要效应。利用CCD成像技术在烟台地区近海面进行了准直高斯光束传输实验,并在实测数据的基础上,分析得到了近海面准直高斯光束的漂移特性。研究结果表明：水平漂移幅度大于垂直漂移幅度,对于1.21 km近海面路径而言,前者介于5.25-10.69 mm之间,后者介于4.45-8.59 mm之间,两者之比的平均数为1.33,小于其他环境下聚焦光束的比值,随着传输距离的增加,它们之间的差异逐渐缩小,夜间时段的比值大于白天时段的比值,并且近海面不同时段的光束漂移幅度差别较小。此外,还对测试期间的大气折射率结构常数进行了简要分析。

Beam wander is an important effect when a beam propagates in atmospheric turbulence. A set of measurements of beam wander of collimated beam using CCD techniques are conducted under the sea surface environment in Yantal region, and the characteristics are analyzed based on the measured data. Results show that the beam wander is larger in the horizontal direction than in the vertical direction, and the amplitude in horizontal direction is between 5.25 mm and 10.69 mm, and in vertical varies from 4.45 mm to 8.59 mm for a 1.21 km optical path. The mean ratio between the standard deviation in two directions is 1.33, and is lower than the value in other environments. The difference between the beam wander in two directions reduces with the increasing propagation distance, and the ratio is larger in nigthttime than in daytime. The beam wander keeps stable at different times. In addition, atmospheric refractive index structure parameter is also analyzed during the test period.