Lenticular array for spatial filtering velocimetry of laser speckles from solid surfaces
Lenticular array for spatial filtering velocimetry of laser speckles from solid surfaces
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DOI：
10.1364/ao.43.004643
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发表时间：
2004-08-20
期刊：
影响因子：
1.9
通讯作者：
Hanson, SG
中科院分区：
文献类型：
--
作者：
Jakobsen, ML;Hanson, SG
我们提出了一种低成本的散斑平移检测光学设计，它可以提供平面内平移或实体结构旋转的测量。用相干光照射非镜面目标表面。散射光通过专门为传感器设计的机械测量类型而设计的光学装置传播。从目标表面产生的散斑场的动力学被投影到透镜阵列上，构成了用于散斑光谱的窄空间带通滤波器。该滤波器提供了对时间准正弦强度输出的全相位信息的访问；因此，光电探测器的差分布置可以抑制低频振荡和高次谐波，并且可以确定散斑平移的方向。对该传感器的空间滤波进行了表征，并研究了该传感器与电子过零检测处理器集成时的精度。恒速测量的最佳精度为1.6 mm平移时的1%，相对标准偏差随行程的平方根减小。(C)2004年美国光学学会。
We present a low-cost optical design for the detection of speckle translation, which can provide measures of in-plane translation or the rotation of a solid structure. A nonspecular target surface is illuminated with coherent light. The scattered light is propagated through an optical arrangement that has been particularly designed for the type of mechanical measurand for which the sensor is intended. The dynamics of the speckle field that arise from the target surface are projected onto a lenticular array, constituting a narrow spatial bandpass filter for the speckle spectrum. The filter provides access to the full phase information of the temporal quasi-sinusoidal intensity output; thus differential arrangements of photodetectors can provide suppression of low-frequency oscillations and higher harmonics, and the direction of the speckle translation can be determined. The spatial filter of the sensor is characterized, and the precision of the sensor when it is integrated with an electronic zero-crossing-detection processor is investigated. The best measurement accuracy obtained at constant velocity is 1% at 1.6-mm translation; the relative standard deviation decreases with the square root of the distance traveled. (C) 2004 Optical Society of America.