Graphene, with its high optical nonlinearity and unique dispersionless nonlinear optical response over a broad wavelength range, has been studied extensively to implement optical devices such as fiber lasers, broadband modulators, polarizers, and optical switches. Conventionally synthesized graphene relying on high temperature and vacuum equipment suffers from deleterious transfer steps that degrade the graphene quality, thereby affecting the efficiency of nonlinear optical operation and lacking the customized patterning with minimized footprint as well as missing the facilitated fabrication process. Here, a laser-aided in situ synthesis of multilayered graphene directly onto the flat surface of a side-polished optical fiber in ambient condition is demonstrated for absolute investigation of an as-grown graphene crystal in the optical domain. The evanescent field of an amplified continuous wave laser, propagating through an optical fiber, provides activation energy for carbon atoms to diffuse through the nickel catalyst and grow graphene directly on the polished side of an optical fiber. Ultrafast all-optical switching near 1550 nm is elucidated by exploiting four-wave mixing with the grown graphene to confirm that the nonlinear response improvement of 58.5% originates from the graphene. The incident signal is modulated at the ultrafast speed of up to 20 GHz, and the modulation information is successfully copied in the newly generated signals at different wavelengths.

中文翻译：

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通过激光的van逝场结合沿光纤生长的原位石墨烯的超快全光开关

石墨烯具有很高的光学非线性特性，并在很宽的波长范围内具有独特的无色散非线性光学响应，因此，人们对其进行了广泛的研究，以实现诸如光纤激光器，宽带调制器，偏振器和光学开关之类的光学器件。依赖于高温和真空设备的常规合成石墨烯遭受有害的转移步骤，该有害的转移步骤降低了石墨烯的质量，从而影响了非线性光学操作的效率，并且缺少具有最小化占用空间的定制图案以及缺少便利的制造工艺。在这里，激光辅助就地已证明在环境条件下将多层石墨烯直接合成到侧面抛光光纤的平坦表面上的化学合成，可用于光学领域中生长石墨烯晶体的绝对研究。放大的连续波激光器的渐逝场通过光纤传播，它为碳原子提供激活能量，使其扩散通过镍催化剂，并在光纤的抛光面上直接生长石墨烯。通过与生长的石墨烯进行四波混合来阐明在1550 nm附近的超快全光切换，以确认58.5％的非线性响应改善源自石墨烯。入射信号以高达20 GHz的超快速度进行调制，并且调制信息已成功复制到新生成的不同波长的信号中。