摘要
高斯光束照射到以角速度ω 旋转的圆柱体表面时,反射空间将出现的动态散斑随着被测表面的运动连续变化,这是一个随机过程。研究了当旋转圆柱体表面满足弱散射体条件时,在菲涅尔衍射场形成的动态散斑的统计特性;给出了几种特定情况下描述动态散斑时间-空间相关性质的参数——动态散斑的空间相关长度,动态散斑的相关时间,动态散斑的平移距离和相关距离。这些参数表明动态散斑的统计特性与圆柱体曲率半径、入射光束、表面微观形貌、物体旋转角速度、光学几何结构因素有关;依据参数分析了动态散斑运动形式,动态散斑纯沸腾运动取决于观察面到散射屏出射平面的距离,投射到散射屏出射平面上的照明光波波面的曲率半径和散射体的曲率半径。
Dynamic speckles appear when a rotating cylindrical object with the angular velocity ω was illuminated by a Gaussian light beam. Speckle pattern on the observation screen changes continuously with object rotating, which is a random process. The statistical properties of dynamic speckles produced in the Fresnel diffraction field by the rotating cylindrical object considered to be a weak phase screen are investigated in detail. The parameters describing the properties of the space-time cross-correlation of dynamic speckles are given under some special conditions, as spatial correlation length, correlation time, translation distance and correlation distance. These parameters show that the statistical properties of dynamic speckles depend on optical conditions, surface roughness, curvature radius and angular velocity of the rotating object as well as geometry structure of optical setup. The motion forms of dynamic speckles are analyzed based on these parameters. From that one can find that the boiling motion of dynamic speckles depends on the distance between the object plane and the observation plane, the wave-front-curvature radius of the beam at the object plane, and the radius of object.
出处
《光电工程》
EI
CAS
CSCD
北大核心
2005年第2期60-63,96,共5页
Opto-Electronic Engineering
关键词
动态散斑
统计特性
高斯光束
旋转柱面
Dynamic speckle
Statistical properties
Gaussian light beam
Rotating cylindrical surface
