We propose and experimentally demonstrate a novel and simple approach to identifying both the direction and value of Doppler frequency shift (DFS) in this paper. A pair of phase modulators, as well as a dispersion medium in between them, are employed in the approach. The different dispersion-induced phase shifts of the upper and lower sidebands after passing the dispersion medium can be used to determine the direction of DFS. The value of DFS is characterized by measuring the frequency of the output signal from a low-speed photodetector. Experimental results verify the feasibility of the approach. The major advantages of the approach lie in that it can measure both the DFS direction and value while avoids the use of complicated modulators and additional reference signal, which greatly simplifies the system's architecture.

中文翻译：

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一种使用色散介质进行多普勒频移测量的光子方法

我们提出并通过实验证明了一种新颖且简单的方法来识别本文中多普勒频移 (DFS) 的方向和值。该方法采用了一对相位调制器，以及它们之间的色散介质。通过色散介质后上边带和下边带的不同色散引起的相移可用于确定 DFS 的方向。DFS 的值通过测量来自低速光电探测器的输出信号的频率来表征。实验结果验证了该方法的可行性。该方法的主要优点在于它可以同时测量 DFS 方向和值，同时避免使用复杂的调制器和额外的参考信号，大大简化了系统架构。