几种设计表面的线性和旋转多普勒频移的实验观察

Experimental Observation of Linear and Rotational Doppler Shifts from Several Designer Surfaces.

作者信息

Liu Baiyang, Chu Hongchen, Giddens Henry, Li Ronglin, Hao Yang

机构信息

Queen Mary University of London, School of Electronics Engineering and Computer Science, London, E1 4NS, UK.

South China University of Technology, School of Electronics and Information Engineering, Guangzhou, 510640, China.

出版信息

Sci Rep. 2019 Jun 20;9(1):8971. doi: 10.1038/s41598-019-45516-1.

DOI:10.1038/s41598-019-45516-1

PMID:31222046

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6586861/

Abstract

An orbital angular momentum (OAM) carrying beam has the ability to detect a spinning surface from its rotational Doppler effect. However, a mixture of linear and rotational Doppler effects can occur when an OAM beam is illuminated to a target, with not only spins but also vibrations. In this paper, we experimentally observe using OAM carrying beams, both linear and rotational Doppler effects from several designer surfaces. Specifically, a spinning polarization-independent metasurface, helicoidal reflector and propeller are applied respectively in this study. We demonstrate by the use of two microwave beams with opposite OAM to separate rotational Doppler shift from micro-Doppler shift. The proposed method can also be applied to measure the spinning speed of rotational objects, which have wider applications in intelligent sensing, radar and quantum optics.

摘要

携带轨道角动量（OAM）的光束能够通过其旋转多普勒效应检测旋转表面。然而，当OAM光束照射到目标上时，不仅存在自旋，还存在振动，此时会出现线性和旋转多普勒效应的混合。在本文中，我们通过实验观察携带OAM的光束从几个设计表面产生的线性和旋转多普勒效应。具体而言，本研究分别应用了旋转偏振无关超表面、螺旋反射器和螺旋桨。我们通过使用具有相反OAM的两束微波光束来证明如何将旋转多普勒频移与微多普勒频移分离。所提出的方法还可用于测量旋转物体的自旋速度，在智能传感、雷达和量子光学等领域有更广泛的应用。