The elastic backscattering of light in optical fiber is a fundamental phenomenon that sets the ultimate performance of several fiber systems such as gyroscopes and bidirectional transfer links. Until now, efforts to reduce the backscattering coefficient have yielded limited results, with the lowest value sitting at around ${-}{{76}}\;{\rm{dB/m}}$ in Ge-free silica-core fiber at 1.55 µm. Here, we present what we believe to be the first measurement of backscattering from a low-loss antiresonant hollow-core fiber and show that it is more than 40 dB below reported values in silica-core fiber and hollow-core photonic bandgap fiber. The record-low level of ${-}{{118}}\;{\rm{dB/m}}$ measured with our custom-built optical frequency-domain reflectometer is in good agreement with simulations in which we assume the scattering to originate from the intrinsic surface roughness. Our demonstration also shows that a tailored instrument can localize and quantify weak faults within a hollow-core fiber, enabling its detailed characterization.

中文翻译：

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反谐振空心光纤的反向散射：比标准光纤低40 dB以上

光纤中光的弹性反向散射是一种基本现象，它决定了陀螺仪和双向传输链路等几种光纤系统的最终性能。到目前为止，降低后向散射系数的努力成果有限，在无Ge硅芯光纤中，最低值约为$ {-} {{76}} \; {\ rm {dB / m}} $在1.55 µm。在这里，我们介绍了我们认为是对低损耗反谐振空心光纤进行反向散射的第一个测量结果，并表明它比硅芯光纤和空心光子带隙光纤的报告值低40 dB以上。的记录低电平{\ RM {分贝/米}} $ - {} {{118}} \ $使用我们定制的光学频域反射仪进行的测量与模拟非常吻合，在模拟中我们假设散射源自本征表面粗糙度。我们的演示还表明，量身定制的仪器可以对空心光纤中的弱故障进行定位和量化，从而对其进行详细表征。