Open AccessLaser heterodyne interferometric signal processing method based on rising edge locking with high frequency clock signal
Author(s) -
Enzheng Zhang,
Benyong Chen,
Liping Yan,
Tao Yang,
Qun Hao,
Wenjun Dong,
Chaorong Li
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.004638
Subject(s) - optics , heterodyne (poetry) , signal (programming language) , interference (communication) , interferometry , signal processing , signal edge , heterodyne detection , digital signal processing , physics , analog signal , laser , computer science , electronic engineering , acoustics , telecommunications , channel (broadcasting) , engineering , programming language
A novel phase measurement method composed of the rising-edge locked signal processing and the digital frequency mixing is proposed for laser heterodyne interferometer. The rising-edge locked signal processing, which employs a high frequency clock signal to lock the rising-edges of the reference and measurement signals, not only can improve the steepness of the rising-edge, but also can eliminate the error counting caused by multi-rising-edge phenomenon in fringe counting. The digital frequency mixing is realized by mixing the digital interference signal with a digital base signal that is different from conventional frequency mixing with analogue signals. These signal processing can improve the measurement accuracy and enhance anti-interference and measurement stability. The principle and implementation of the method are described in detail. An experimental setup was constructed and a series of experiments verified the feasibility of the method in large displacement measurement with high speed and nanometer resolution.