基于石墨烯-雕塑薄膜超材料增强的光控太赫兹光纤调制器的研究

高平均功率太赫兹自由电子激光装置（CTFEL）具有高重复频率，高峰值亮度等特点，对幅度调制器提出了快调制速率、大调制深度和良好稳定性等要求。区别于空间光控方式，本项目基于石墨烯超快光控响应特性，将石墨烯-雕塑薄膜超材料集成于侧边抛磨太赫兹光纤上，形成的新式光控光纤调制器，具有快调制速率、低泵浦光功率、大调制深度和良好稳定性。项目重点围绕光控光纤调制器的物理机制、优化设计、制备工艺以及性能检测开展研究。本项目创新地采用石墨烯和具有纳米结构的雕塑薄膜构建超材料，同时增强近红外泵浦光、太赫兹光与石墨烯相互作用，从而降低泵浦光功率，提升调制深度；采用侧边抛磨太赫兹光纤增加光与石墨烯相互作用长度，同时降低环境水蒸气影响，提升器件稳定性。基于石墨烯-雕塑薄膜超材料增强的光控太赫兹光纤调制器结构紧凑，既聚焦世界范围内的前沿研究热点，也切合CTFEL的应用需求，有望推动光控光纤器件在太赫兹光前沿领域的应用

The high average power terahertz free electron laser device (CTFEL) has the characteristics of high repetition frequency, high peak brightness. CTFEL requires fast modulation rate, large modulation depth and good stability for the amplitude modulator. Different from the spatial optically controlled method, the graphene-sculptured film metamaterial is integrated on the side-polished terahertz fiber based on the ultra-fast optically controlled response of graphene. The new optically controlled fiber modulator shows a fast modulation rate, low pump light power, large modulation depth, and good stability characteristics. This project focuses on the physical mechanism, optimized design, manufacturing process and performance testing of optically controlled fiber modulator. The graphene and sculptured film with nano-structure are innovatively used to build a metamaterial in the project. The metamaterial enhances the interaction between near-infrared pump light, terahertz light and graphene, which reduces the pump light power and improves the modulation depth. The side-polished terahertz optical fiber is used to increase the interaction length between light and graphene, while reducing the effect of environmental water vapor and improving the stability of the device. The optically controlled terahertz fiber modulator based on the sculptured thin film-graphene metamaterial has a compact structure, which not only focuses on the leading research hotspots in the world, but also meets the application requirements of CTFEL. The optically controlled terahertz fiber modulator is expected to promote the application of optically controlled fiber devices in the frontier of terahertz light.