We created an all-fiber solution for fast, continuous, and controllable tuning of Fano-like resonance. By embedding a graphene-coated fiber Bragg grating into one arm of a Mach–Zehnder interferometer, the narrow Bragg resonance interacts with a broad interference spectrum, forming a sharp asymmetric Fano-like resonance line shape. With the application of an electrical voltage over the graphene layer, the generated Joule heating shifts the Bragg resonance and consequently tunes the asymmetric Fano-like resonance line shape to a symmetric dip or electromagnetically induced transparency-like peak. Further, by exploiting two modulated states with reversed Fano-like resonance line shapes, an optical switch can operate with an extinction ratio of 9 dB. The well-engineered Fano-like resonance in an all-fiber structure opens up new horizons for applications of fiber gratings in optical signal processing, slow-light lasing, and fiber sensing.

中文翻译：

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石墨烯涂层光纤光栅中的电诱导动态类 Fano 共振

我们创建了一种全光纤解决方案，用于快速、连续和可控地调节 Fano 类共振。通过将石墨烯涂层光纤布拉格光栅嵌入马赫-曾德干涉仪的一个臂中，窄布拉格共振与宽干涉光谱相互作用，形成尖锐的不对称 Fano 状共振线形状。通过在石墨烯层上施加电压，产生的焦耳热使布拉格共振发生偏移，从而将不对称的类 Fano 共振线形状调整为对称的倾角或电磁感应的类透明峰。此外，通过利用具有反向 Fano 类谐振线形状的两种调制状态，光开关可以以 9 dB 的消光比工作。