转动干版的平面波多光束全息干涉计量的研究

Multibeam Holographic Interferometry by Rotating-Plate Method under Planar-Wave Illumination

本文提出了一种转动干版的多光束全息干涉计量术,用于测量试件的三维振幅场。该全息干涉计量术采用的光路系统具有空间分布的三束平面波物光和一束平面波参考光。它借助于一个可使干版作任意角度转动的特殊装置,在一张干版上记录振动体同一谐振频率的三个独立的时间平均全息图。再现时,该干版用原参考光照射,并分别转到记录时的三个原始位置,则可得到三个时间平均干涉图。利用有关的物理模型,便可导出求解被测物体上任一点的振幅的三个分量的线性方程组。该全息干涉计量术的特点是光路结构不太复杂,多个干涉图的记录、再现和采集很方便;相应物理量的分析计算非常简单。本文还对该全息测振法的测量精度进行了研究。最后以叶片为试件作了实验验证。

Interferometry of multiple-beam holography by rotating plate is proposed to measure 3D amplitude of the test object. The optical system of this kind of holographic in-teferometry has the three planar-wave object beams of spatial distribution and a planar-wave reference beam. The three independent time-average holograms of the vibrating object under the same frequency are recorded on a plate with the help of a special unit that enables the plate to rotate at an arbitrary angle.During reconstruction,this plate is illuminated with the original reference beam, and is rotated to the three original positions of recording, then the three time-average interferograms of the above frequency can be obtained. Utilizing the related physical model, the linear system of equations solved for the three components of the amplitude of the arbitrary point on the test object may be derived. The properties of the holographic interferometry proposed in this paper are that the construction of the optical system is simple, the record, reconstruction and sampling of the multiple interferograms are very convenient,and the analysis and calculation of the physical quantities corresponding to these interferograms are very simple as well. In addition,in order to improve the precision of the analysis,this paper has also discussed the problem of vibration error measured by the above holographic method. Finally, an experimental demonstration has been done by using the vane (JT-1) as the test object.