Extremely strong bipolar optical interactions in paired graphene nanoribbons
Extremely strong bipolar optical interactions in paired graphene nanoribbons
复制标题
成对石墨烯纳米带中极强的双极光学相互作用
DOI：
10.1039/c5cp06581j
复制
发表时间：
2016
影响因子：
3.3
通讯作者：
Lin Zhifang
中科院分区：
文献类型：
--
作者：
Lu Wanli;Chen Huajin;Liu Shiyang;Zi Jian;Lin Zhifang
石墨烯是一个优秀的多功能平台的电子，光子和声子由于特殊的电子，光子和热性能。当将其非凡的机械特性与光学特性相结合时，石墨烯基纳米结构可以作为纳米级光机械应用的吸引人的平台。在这里，我们证明，使用全波模拟，出现极强的双极光学力，或光学绑定和反绑定，一对耦合的石墨烯纳米带之间，由于显着的限制和增强的光场所产生的大的有效模式指数。特别地，比超材料和高Q谐振器中强大约两个数量级的结合力和反结合力可以通过选择性地激发偶数或奇数光学模式来定制，这可以通过调谐沿着沿着两个带传播的光波的相对相位来实现。基于耦合模理论，我们推导了双极光学力的解析表达式，与数值计算结果符合得很好。吸引的光学结合力Fby和排斥的反结合力Fay对纳米带之间的差距距离g和费米能EF表现出显著不同的依赖性，其形式为和Fay = 1/E2 F。随着EF动态可调的偏置电压，双极性力可以提供一个灵活的处理，主动控制的纳米级光机械效应，也可能是重要的光电和光热应用。
Graphene is an excellent multi-functional platform for electrons, photons, and phonons due to exceptional electronic, photonic, and thermal properties. When combining its extraordinary mechanical characteristics with optical properties, graphene-based nanostructures can serve as an appealing platform for optomechanical applications at the nanoscale. Here, we demonstrate, using full-wave simulations, the emergence of extremely strong bipolar optical forces, or, optical binding and anti-binding, between a pair of coupled graphene nanoribbons, due to the remarkable confinement and enhancement of optical fields arising from the large effective mode indices. In particular, the binding and anti-binding forces, which are about two orders of magnitude stronger than that in metamaterials and high-Q resonators, can be tailored by selective excitation of either the even or the odd optical modes, achievable by tuning the relative phase of the lightwaves propagating along the two ribbons. Based on the coupled mode theory, we derive analytical formulae for the bipolar optical forces, which agree well with the numerical results. The attractive optical binding force Fby and the repulsive anti-binding force Fay exhibit a remarkably different dependence on the gap distance g between the nanoribbons and the Fermi energy EF, in the forms of and Fay ∝ 1/E2F. With EF dynamically tunable by bias voltage, the bipolar forces may provide a flexible handle for active control of the nanoscale optomechanical effects, and also, might be significant for optoelectronic and optothermal applications as well.