乌氏干涉测量的信息读取

针对乌氏干涉仪条纹信号调整难、用肉眼读数难等问题,提出将He-Ne激光作为乌氏干涉仪光源的设计,得到了高质量的干涉条纹信号,并采用光电转换方法将条纹移动信号转变为电信号实现了微位移的高精度测量。设计了光电信号检测电路,利用双门限整形电路标定出整形方波,克服了干涉信号在设定比较值附近抖动引起误处理的缺点;提出了辨向细分电路,在1路干涉条纹信号下,提取了具有正交性的2路电子信号,实现了干涉条纹的移动辨向与信号细分。按此方案设计并搭建了一套激光干涉检测实验装置,用2个计量差值为5μm的标准量块,对激光干涉检测装置进行了标定,在电路为4细分的情况下,该装置测量分辨率达79 nm;解决了乌氏干涉仪自动读数的问题,提高了乌氏干涉仪的测量精度和准确性。

Information reading of Ubbelohde interferometry

For the shortcomings of the interference fringe difficult to read and adjust in an Ubbelohde interferometer,a He-Ne laser was used in the Ubbelohde interferometer as the source to offer interference fringe signals with high quality.Then,the fringe signals were transform into electron signals to implement the micro-displacement measurement precisely.A detection circuit was designed and the square wave signal was extracted by using a dual-threshold shaping circuit,which solveed the error processing problem when signals jittered near the set comparison value.A discerning direction and subdividing circuit was designed and the orthogonal electron signals were extracted to achieve the discerning direction of interference fringe movement and the subdivision of interference signals.On the schemes above,a laser interference detection device was designed and built.The device was calibrated by two standard gauge blocks with a difference value of 5 μm.Under four subdividing circuits,the resolution of the detecting device is 79 nm.Therefore,the Ubbelohde interferometer achieveds automatic reading and improves its measurement precision.