纳米级位移分辨率双光栅系统的多普勒分析

Doppler analysis for double-grating displacement measurement s ystem with nanometer resolution

使用多普勒理论分析了一种典型的具有纳米级位移分辨率的双光栅测量系统。在以往的文献中 ,只是简单的列出光栅系统的位移测量公式 ,对系统的工作原理分析避而不谈。文中首先给出了系统的光路结构 ,分析了光栅的衍射序列 ,然后对光束入射和出射光栅的多普勒效应进行了数学建模 ,得到了最终的位移测量值与光学莫尔条纹之间的关系。最后分析了参考光栅的作用 ,并给出了这种系统的特点。

Unlike other papers which listed the measuring equation only, and didn't touch t he operation principle, a double-grating displacement measurment system with a resolution of one nanometer is analyzed using Doppler theory in this paper. The optical structure of the gr a ting system is first shown in detail, the diffraction sequences are described in turn, a mathematic model of incident and emission light beam is then establishe d for Doppler effect, and finally the relationship between the displacement valu e and the corresponding Moiré signals is established with this model. The function of refere nce grating is ex plained, and the characteristics of this grating system are listed.