Liang Yu-Rong, Duan Hui-Zong, Yeh Hsien-Chi, Luo Jun
MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074, People's Republic of China.
Rev Sci Instrum. 2012 Sep;83(9):095110. doi: 10.1063/1.4751867.
Ultra-precision phase measurement is a key technology for state-of-the-art laser interferometry. In this paper we present a fully digital phase measurement method based on cross-correlation analysis, and analyze the measurement errors caused by sampling quantization, intrinsic white noise and non-integral-cycle sampling. The last error source results in a cyclic error that has not been reported ever. We used a high-performance data acquisition system to carry out the cross-correlation-based phase measurement, and obtained a noise level of 1.2 × 10(-6) rad/Hz(1/2)[commercial at]1 Hz. Moreover, the cyclic phase error of about 10(-2) rad/Hz(1/2), caused by non-integral-cycle sampling, had been observed. In order to demonstrate the application of this precision phase measurement method, an ultra-precision heterodyne laser interferometer, consisting of digital phase measurement system and ultra-stable optical bench, was constructed for displacement measurement. The experimental results showed that a measurement resolution of 63 pm had been achieved.
超精密相位测量是先进激光干涉测量技术的一项关键技术。本文提出了一种基于互相关分析的全数字相位测量方法，并分析了由采样量化、固有白噪声和非整周期采样引起的测量误差。最后一个误差源会导致一种从未被报道过的周期性误差。我们使用高性能数据采集系统进行基于互相关的相位测量，在1 Hz时获得了1.2×10(-6) rad/Hz(1/2)的噪声水平。此外，还观测到了由非整周期采样引起的约10(-2) rad/Hz(1/2)的周期性相位误差。为了演示这种精密相位测量方法的应用，构建了一种由数字相位测量系统和超稳定光学平台组成的超精密外差激光干涉仪用于位移测量。实验结果表明，实现了63 pm的测量分辨率。
