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微小尺寸的测量多采用大琅和费衍射法测量,因为其衍射暗纹间距与被测尺寸之间具有很简单的线性关系.实用中,夫琅和费衍射占用空间很大.而且衍射图象与传感器尺寸很难匹配.通过对菲涅尔衍射和夫琅和费衍射光强分布的深入研究,发现二者暗纹分布是相同的.本项研究将衍射测量扩展到菲涅尔衍射区,不但可以扩展测量范围,还可以通过扩大所接受衍射谱级次的方法,提高测量精度,具有较高的实用价值,理论上也有一定突破.“,”Diffraction measurement for micro-size is mostly based on Fraunhofer theory, because ofsimple linear function between the space of dark stripes ofdiffraction spectrum and the size to be measured. Inpractice, Fraunhofer diffraction take more space than Fresnel and it is difficult to matching the size to be measured and the size of sensor. This study focus on light intense arrangements of Fraunbofer and Fresnel diffraction, found that both dark stripes are located on same positions, so that diffraction measuremellt is extended into Fresnel diffraction domain. This project can not only eXtend measuring ranges but also increasemeasuring accuracy by receiving more diffraction stripes.