A Six-Axis Heterodyne Interferometer System for the Joule Balance

作者：Bai, Yang; Hu, Pengcheng^*; Lu, Yunfeng; Li, Zhengkun; Zhang, Zhonghua; Tan, Jiubin

来源：IEEE Transactions on Instrumentation and Measurement, 2017, 66(6): 1579-1585.

DOI：10.1109/TIM.2016.2634758

• Feedback control
• joule balance
• laser interferometer
• measurement uncertainty
• periodic nonlinearity

A six-axis heterodyne interferometer system has been designed for the joule balance to measure the relative displacement between the suspended coil and the exciting coil. The essential optical components in this system are three dual-axis heterodyne interferometers. Each interferometer can simultaneously measure the displacements of one retro-reflector (RR) on the suspended coil and one RR on the exciting coil. Because of the common path structure, this interferometer is susceptible to periodic nonlinearity caused by double-frequency mixing. However, a method can be used to eliminate the periodic errors. The measured displacements can be strictly locked to integral multiples of half the wavelength. This method was theoretically analyzed and finally verified by the experiment.

• 出版日期2017-6
• 单位中国计量科学研究院; 哈尔滨工业大学