液体基准平面的Φ300 mm立式斐索干涉仪系统误差标定

System error calibration forΦ300 mm vertical Fizeau interferometer based on liquid reference

在高精度的干涉检测中,干涉仪系统误差的标定越来越重要。根据立式斐索干涉仪的结构特点,采用液面作为平面基准,对参考平晶的自重变形量以及夹持形变进行补偿校准,对其系统误差进行标定。理论上,液面和地球半径的曲率相同,可认作平面基准对立式结构干涉仪的系统误差进行标定。针对Φ300 mm立式斐索干涉仪,研究了不同的液体粘度、液体厚度、干涉腔长和环境温度对液面测量的影响,构建了可靠的液面基准。通过液面基准,指导干涉仪参考平晶的装调校准,对其系统误差进行补偿,干涉仪精度达到0.035λ,优于λ/25。为了进一步验证液面基准的可靠性与准确性,进行了重复性实验,并且采用Φ400 mm的液面和Φ450 mm的液面进行比对测试,两次标定结果的偏差优于λ/100(6 nm),验证了液面基准的可靠性与准确性。

In high-precision interference detection,the calibration of interferometer system errors was important.According to the structural characteristics of the vertical Fizeau interferometer,the liquid reference plane was used as a reference to compensate and calibrate the self-weight deformation and clamping deformation of the reference flat crystal,and calibrate its system error.Theoretically,the curvature of the liquid surface and the radius of the earth were the same,which can be regarded as a plane reference to calibrate the system error of the vertical structure interferometer.For theΦ300 mm vertical Fizeau interferometer,the influence of different liquid viscosity,thickness,interference cavity length and temperature was studied,and a reliable liquid reference plane reference was constructed.Through the liquid reference plane,the interferometer was guided to refer to the installation and calibration of the reference flat crystal,and its system error was compensated.The accuracy of the interferometery reached 0.035λ,which was better thanλ/25.In order to further verify the reliability and accuracy of the liquid reference plane,repeatability experiments were carried out,and the liquid reference plane ofΦ400 mm andΦ450 mm were used for comparison test.The deviation of the two calibration results was better thanλ/100(6 nm).The reliability and accuracy of the liquid reference plane were verified.