自动读出旋光准直测量系统

Automatic Straightness Measurement System Based on Polarimetry

本文介绍了旋光准直仪的原理和系统的结构。给出了自动读出方法的依据和实测结果。这种方法可以用于直线度测量、检糖仪和偏振光干涉仪的条纹细分。

In this paper,the principle and diagram of the automatic straig-htness measurement systen is introduced.A pair of Glan prisms served as thepolarizer and the analyzer.A modulating and compensating Faraday rotator we-re placed in the optical path.Modulation was drived from a sine wave gener-ator and amplifier.The sensor consists of a pair of left-handed and right-han-ded quartz wedge with 1°angle.Light vibrations are rotated by different amou-nts according to the portion of the wedge through which they have passed.Conventionally the rotation angle is measured by current in compensatingsolenoid at the moment of extinction.An automatic demodulation method is ba-sed on the signal analysis received.In one period of driving wave there are fourextrema.We take the voltage at first and third extremum(v1 and v3)and let:P =(v1-v3)/(v1+v3),then P is proportional to the displacement of quartzwedge.This method proved to be true theoretically and experimentally.Calibrate itagainst MILLITRON indicator and have the linearregression,the Correlationcoefficient is 0.998,the standard diviation is 1 um.It Can be used not only in straightness measurement but also in saccharimeterand polarization interferometer as well as in chromatographic detection.The in-strument we have made has been used in industrial environment.