基于物体对称性实现旋转多普勒效应的优化测量

Optimal Measurement of Rotation Doppler-frequency Shifts Based on Rotational Symmetry

为了快速高效地测量对称物体的转速,基于数字螺旋成像理论,提出了一种测量旋转多普勒频移的优选方案.通过在空间光调制器上加载多重对称性物体的旋转光栅来模拟旋转物体.实验中通过测量三重对称物体和十重对称物体的反射谱,分析其频谱特性,验证了该方案可以快速高效地得到高信噪比的信号,进而测得转速,且测量误差在0.7%左右.该方法对测量具有多重对称性的物体的转速高效准确,有望应用在遥感技术领域,甚至在天文领域探测天体转速.

In order to quickly and efficiently measure the rotational speed of the symmetric, we devise an optimal method with high coupling efficiency to measure the rotational Doppler-frequency shifts by analyzing the orbital angular momentum of the light scat- tered from a rotating mask based on the digital spiral imaging theory.In our experiment, the rotating object is mimicked by holograms of special symmetry displayed on the spatial light modulator.The experimental results show that the proposed scheme can ob- tain the oribital angular momentum （OAM） spectrums of clover and ten leaf clover with high signal-to-noise ratio quickly and effi- ciently.Compared with the theoretical results, the error in our experiments is about 0.7 %.Our scheme offers a high-efficiency method of Doppler-frequency shift measurement,adding the potential for remote detection of spinning objects.