Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201800, China.
Rev Sci Instrum. 2023 Jan 1;94(1):013105. doi: 10.1063/5.0116933.
A metrology device based on the near-field speckle technique was developed in the x-ray test beamline at the Shanghai Synchrotron Radiation Facility to meet the at-wavelength detection requirements of ultra-high-precision optical elements. Different sources of error that limit the uncertainty of the instrument were characterized. Two main factors that contribute to the uncertainty of the measurements were investigated: (1) noise errors introduced by the electronics and the errors introduced by the algorithm and (2) stability errors owing to environmental conditions. The results show that the high measurement stability of the device is realized because it is insensitive to the effect of the external environment. The repetition accuracy of the device achieved 9 nrad (rms) when measuring the planar mirror that produces weak phase curvature.
基于近场散斑技术的计量设备在上海同步辐射装置的 X 射线测试光束线中开发出来，以满足超高精度光学元件的波长检测要求。对限制仪器不确定度的不同误差源进行了特征描述。研究了导致测量不确定度的两个主要因素：（1）由电子设备引入的噪声误差和由算法引入的误差；（2）由环境条件引起的稳定误差。结果表明，由于该设备对外部环境的影响不敏感，因此实现了高测量稳定性。在测量产生弱相位曲率的平面反射镜时，该设备的重复精度达到了 9 nrad（均方根值）。
