Qiu Song, Ren Yuan, Liu Tong, Li Zhimeng, Liu Zhengliang, Wang Chen, Ding You, Sha Qimeng
Opt Express. 2021 Mar 29;29(7):10275-10284. doi: 10.1364/OE.421705.
The capability to detect the rotational speed of non-cooperative targets in a long distance is a difficult problem to be solved. In recent years, vortex light provides a feasible solution for the measurement of rotational speed for its spiral phase and the orbital angular momentum. Laguerre-Gaussian (LG) mode, as the typical vortex beam, has been widely employed in rotational Doppler effect (RDE) experiments. Here, we show that the nonzero radial index LG beam not only has a specific physical meaning but also can enhance the light intensity and the amplitude of RDE frequency signal relative to a zero radial index LG beam. To this end, we theoretically analyze the reason of intensity enhancement of a nonzero radial index beam and verify the conclusion in a variable control experiment. Our study provides a new aspect of LG beams that can be considered in rotational speed detection based on RDE. It may produce an improvement of the detection range of rotating targets in practical applications.
远距离探测非合作目标转速的能力是一个亟待解决的难题。近年来，涡旋光因其螺旋相位和轨道角动量为转速测量提供了一种可行的解决方案。拉盖尔 - 高斯（LG）模式作为典型的涡旋光束，已被广泛应用于旋转多普勒效应（RDE）实验。在此，我们表明非零径向指数LG光束不仅具有特定的物理意义，而且相对于零径向指数LG光束，还能增强光强和RDE频率信号的幅度。为此，我们从理论上分析了非零径向指数光束光强增强的原因，并在变量控制实验中验证了这一结论。我们的研究为基于RDE的转速检测提供了LG光束可考虑的新方面。它可能在实际应用中提高旋转目标的探测范围。
