Zhuang Huawei, Kong Fanmin, Li Kang, Sheng Shiwei
Appl Opt. 2015 Apr 1;54(10):2558-64. doi: 10.1364/AO.54.002558.
A plasmonic bandpass filter based on graphene is proposed and numerically investigated using the finite-difference time-domain method. The proposed filter has a very simple structure, including two graphene nanoribbon waveguides laterally coupled to a graphene ribbon resonator. The transmission efficiency can be tuned by altering the coupling distance between the ribbons. At the same time, the variation of the transmission spectra is investigated by tuning the size of the graphene resonant ribbon. Notably, due to the unique electronic tunability of graphene, the transmission spectra can be freely tuned in a broad frequency range by choosing the chemical potential, which exhibits more flexible tunability than that used in conventional metallic devices. Attributed to the standing wave distribution of different modes excited in the graphene resonant ribbon, the proposed filter can be used for the plasmonic device with the capability of band selection or power splitting by locating the output waveguide ports in the suitable positions.
提出了一种基于石墨烯的表面等离子体带通滤波器，并采用时域有限差分法对其进行了数值研究。所提出的滤波器结构非常简单，包括两个横向耦合到石墨烯带状谐振器的石墨烯纳米带波导。通过改变带之间的耦合距离可以调节传输效率。同时，通过调整石墨烯谐振带的尺寸来研究传输光谱的变化。值得注意的是，由于石墨烯独特的电子可调性，通过选择化学势，可以在很宽的频率范围内自由调节传输光谱，这比传统金属器件具有更灵活的可调性。由于在石墨烯谐振带中激发的不同模式的驻波分布，通过将输出波导端口定位在合适的位置，所提出的滤波器可用于具有选带或功率分配能力的表面等离子体器件。
