Compensation for the Variable Cyclic Error in Homodyne Laser Interferometers

• Main Authors: Pengcheng Hu, Jinghao Zhu, Xuanbiao Guo, Jiubin Tan
• Format: Article
• Language: English
• Published: MDPI AG 2015-01-01
• Series: Sensors
• Subjects: homodyne interferometer; quadrature signal; cyclic error compensation
• Online Access: http://www.mdpi.com/1424-8220/15/2/3090

This paper presents a real-time method to compensate for the variable cyclic error in a homodyne laser interferometer. The parameters describing the quadrature signals of the interferometer are estimated using simple peak value detectors. The cyclic error in the homodyne laser interferometer was then corrected through simple arithmetic calculations of the quadrature signals. A field programmable gate array was utilized for the real-time compensation of the cyclic error in a homodyne laser interferometer. The simulation and experimental results indicated that the proposed method could provide a cyclic error that was fixed without compensation down to a value under 0.6 nm in a homodyne laser interferometer. The proposed method could also reduce the time-varying cyclic error to a value under 0.6 nm in a homodyne laser interferometer, in contrast to the equivalent value of 13.3 nm for a conventional elliptical fitting method.