Lau效应的扩展及其在位移测量中的应用

Extension of the Lau Effect and Its Application in Displacement Measurement

本文研究在扩展光照明下双光栅的相互作用,将光栅间的相互作用作为光栅对光栅的成像过程,基于非相干成像理论导出了成像条件,分析了成像特性。这种光栅成像可作为是对Lau效应的进一步扩展。本文进而研究了这种原理在位移测量中的应用,导出基于这种光栅成像原理的光栅位移传感器的莫尔条纹方程,并对位移传感器进行了实验。结果表明:这种光栅位移传感器具有结构简单,无需采用准直光源照明,并且能在大光栅间隙下工作的特点。

The interaction between two gratings by illumination with an extended light is investigated. This interaction is considered as an imaging process, where a grating is imaged by a second grating. Based on the incoherent imaging theory,the imaging conditions have been derived and the imaging properties are discussed. This grating imaging is explained as an extension of the Lau effect. The application of the grating imaging to displacement measurement is also studied in this paper. The expression of the Moire fringes of the grating displacement transducer using grating imaging principle has been derived. The experimental results of the transducer are given. This grating displacement transducer has many advantages,such as simplicity of structure.no need of collimated light illumination, and it can be used in the condition of large grating gap.