利用石墨烯优越的光学性能, 构建了基于全光纤结构的石墨烯电吸收调制器。设计了调制器的结构, 并进行了仿真和实验双重研究。首先, 根据石墨烯的光学可调特性研究了其化学势和介电常数之间的关系。接着, 基于全光纤结构设计了石墨烯电吸收调制器, 并分析了它的整体有效折射率和化学势的变化关系。对提出的光纤石墨烯调制器进行仿真分析, 并与传统半导体电吸收调制器进行对比, 实现了一个全光纤结构的石墨烯调制器。对实现的调制器进行了系统的性能测试。结果显示: 仿真的四层石墨烯的全光纤电吸收调制器的调制效率可以达到0.233 dB/mm, 在12.9 mm的长度上可实现0.2 V的摆动电压。实验测试验证了提出的全光纤石墨烯调制器的可行性; 但受实验条件的限制, 其半波电压约为120 V, 3 dB调制器带宽为100 MHz。与传统石墨烯波导调制器相比, 提出的调制器显示了半波电压小, 调制效率高, 尺寸小, 同时具有低的插入损耗低等优势, 适合在未来全光纤RoF系统应用。

On the excellent optical performance of grapheme, a graphene-based all-fiber electro-absorption modulator was constructed. The structure of the modulator was designed, and simulation and experiments for the modulator were both conducted. Firstly, the relationship between the chemical potential and the permittivity was researched according to the graphenes optical properties, then the graphene-based all-fiber modulator was designed, and the dependence of the effective refractivity of the modulator on the chemical potential was analyzed. The proposed graphene-based all-fiber electro-absorption modulator was simulated and was compared to traditional semiconductor modulators. Finally, the graphene-based all-fiber electro-absorption modulator was developed and its performance was tested. The simulation results show that the modulation efficiency of the quadri-layer all-fiber graphene modulator reaches up to 0.233 dB/mm, and the footprint has been reduced to only 12.9 mm with the swing voltage lower than 0.2 V. The experiments demonstrate that the proposed modulator is feasibility. Limited by the practical conditions, the tested half-wave voltage is about 120 V and the 3 dB bandwidth is around 100 MHz. As compared with traditional graphene-based waveguide modulator, the proposed modulator shows a smaller half-wave voltage, higher modulation efficiency, and a smaller size. Moreover, it has a lower insert loss and is suitable for all-fiber systems in future.