Noncoaxial RDE of circular asymmetry optical vortex for rotating axis detection  

作　　者：SONG QIU XIANGYANG ZHU RUOYU TANG TONG LIU RUIJIAN LI YUAN REN 

机构地区：[1]Department of Aerospace Science and Technology,Space Engineering University,Beijing 101416,China [2]Lab of Quantum Detection&Awareness,Space Engineering University,Beijing 101416,China [3]Department of Basic Course,Space Engineering University,Beijing 101416,China

出　　处：《Photonics Research》2022年第11期2541-2548,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(62173342,61805283);Key Research Projects of Foundation Strengthening Program of China(2019-JCJQ-ZD)。

摘　　要：We reveal the mechanism of the noncoaxial rotational Doppler effect(RDE) of an optical vortex and report its application in discriminating the orientation of the rotating axis of the rotating body. In most cases of the RDEbased measurement, the beam axis must be aligned with the rotating axis of the rotational body to observe a good signal. Once the beam axis is not coaxial with the rotating axis, the RDE frequency shift would change related to the misalignment distance, which can be called the noncoaxial RDE. Here, we take the advantage of the misaligned RDE augment with precise light-field modulation and successfully realize the discrimination of the orientation of the rotating axis relative to the illuminating beam. We clarify the principle of noncoaxial RDE and explain why the incomplete optical vortex(OV) is sensitive to the position of the rotating axis. We switch the OV field into four quadrants synchronized with sampling by the data acquisition system, and conduct Fourier transformation of the signals. Combined with the fitting algorithm, the orientation of the rotating axis can be recognized directly. This method may find applications for the noncontact detection of rotating bodies in both industrial and astronomical scenarios.

关 键 词：COAXIAL OPTICAL ROTATING 

分 类 号：O43[机械工程—光学工程]