Nazemosadat Elham, García Sergi, Gasulla Ivana
Opt Express. 2022 Jul 18;30(15):26886-26895. doi: 10.1364/OE.463152.
A novel microwave frequency measurement scheme using a heterogeneous multicore fiber (MCF) is experimentally demonstrated. The inherently different relative group delays among the cores of a heterogeneous 7-core MCF are used to realize two individual 2-tap microwave filters with different free spectral ranges (FSRs). The ratio of the frequency response traces of these two filters is used to establish an amplitude comparison function (ACF). Furthermore, by varying the operational wavelength, the relative group delays between the cores and consequently the FSRs of the filters are tuned and different ACF curves are obtained. The complementary information provided by these different ACFs allows us to estimate the unknown frequency with an improved accuracy, over a broad measurement range. In our experiments, a measurement error of ±71 MHz is achieved over a frequency range of 0.5-40 GHz. The proposed scheme offers flexibility and compactness, thanks to the parallelism provided by the MCF.
通过实验证明了一种使用异质多芯光纤（MCF）的新型微波频率测量方案。利用异质7芯MCF各芯之间固有的不同相对群延迟来实现两个具有不同自由光谱范围（FSR）的独立2抽头微波滤波器。这两个滤波器频率响应轨迹的比值用于建立幅度比较函数（ACF）。此外，通过改变工作波长，可以调整各芯之间的相对群延迟，从而调整滤波器的FSR，并获得不同的ACF曲线。这些不同ACF提供的互补信息使我们能够在较宽的测量范围内以更高的精度估计未知频率。在我们的实验中，在0.5 - 40 GHz的频率范围内实现了±71 MHz的测量误差。由于MCF提供的并行性，所提出的方案具有灵活性和紧凑性。
