Externally pumped low-loss graphene-based fiber Mach-Zehnder all-optical switches with mW switching powers
Externally pumped low-loss graphene-based fiber Mach-Zehnder all-optical switches with mW switching powers
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DOI：
10.1364/oe.27.004216
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发表时间：
2019-02-18
期刊：
影响因子：
3.8
通讯作者：
Chiang, Kin Seng
中科院分区：
文献类型：
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作者：
Hao, Ting;Chang, Zeshan;Chiang, Kin Seng
我们提出并通过实验演示了一种基于石墨烯涂层光纤马赫-曾德尔干涉仪的全光开关，其中干涉仪一个臂中信号光的相位通过石墨烯涂层吸收外部泵浦光产生的热量而改变。外部泵浦方案通过在普通光纤或稍微锥形光纤上涂覆多层石墨烯来实现有效的泵浦吸收，而不会引入显着的额外信号损失。在不使用任何波长复用器/解复用器的情况下，开关可以在任何方便的波长甚至宽带光下进行泵浦。我们的实验装置基于具有 5 毫米长石墨烯涂层的标准 125 微米直径单模光纤，可以在 19 dB 消光比下以 5.3 mW 的泵浦功率进行切换，而不会产生额外的信号损失。开关功率对石墨烯涂层的长度不敏感，当光纤逐渐变细至 40 μm 时，开关功率可降至 4.8 mW。测量的开关功率与通过将石墨烯涂层视为无厚度的均匀热源片而获得的理论值非常吻合。开关的响应时间随着纤维直径的增加而减少，并且与石墨烯涂层的长度成反比。该开关的上升和下降时间基于具有 20 毫米长石墨烯涂层的 40 微米锥形光纤，分别为 30 毫秒和 50 毫秒。 (C) 2019 年美国光学学会根据 OSA 开放获取出版协议条款
We propose and experimentally demonstrate an all-optical switch based on a graphene-coated fiber Mach-Zehnder interferometer, where the phase of the signal light in one arm of the interferometer is changed by the heat generated from external pump light absorption by the graphene coating. The external pumping scheme allows efficient pump absorption with multiple layers of graphene coated on an ordinary fiber or a slightly tapered fiber without introducing significant additional signal loss. Without using any wavelength multiplexer/demultiplexer, the switch can be pumped at any convenient wavelength or even with broadband light. Our experimental device, which is based on a standard 125-mu m-diameter single-mode fiber with a 5-mm-long graphene coating, can be switched with a pump power of 5.3 mW at an extinction ratio of 19 dB with no additional signal loss. The switching power is insensitive to the graphene coating's length and can be reduced to 4.8 mW, with the fiber tapered to 40 mu m. The measured switching powers agree well with the theoretical values obtained by treating the graphene coating as a uniform sheet of heat source without thickness. The switch's response time decreases with the fiber diameter and inversely with the graphene coating's length. The switch's rise and fall times, based on a 40-mu m tapered fiber with a 20-mm-long graphene coating, are 30 ms and 50 ms, respectively. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement