Cheng Yue, Yang Jingjing, Lu Qiannan, Tang Hao, Huang Ming
Wireless Innovation Lab of Yunnan University, School of Information Science and Engineering, Kunming 650091, Yunnan, China.
Radio Monitoring Center of Yunnan Province, Kunming 650228, Yunnan, China.
Sensors (Basel). 2016 May 27;16(6):773. doi: 10.3390/s16060773.
Due to its adjustable electronic properties and effective excitation of surface plasmons in the infrared and terahertz frequency range, research on graphene has attracted a great deal of attention. Here, we demonstrate that plasmon modes in graphene-coated dielectric nanowire (GNW) waveguides can be excited by a monolayer graphene ribbon. What is more the transverse resonant frequency spectrum of the GNW can be flexibly tuned by adjusting the chemical potential of graphene, and amplitude of the resonance peak varies linearly with the imaginary part of the analyte permittivity. As a consequence, the GNW works as a probe for capturing the molecular spectrum. Broadband sensing of toluene, ethanol and sulfurous anhydride thin layers is demonstrated by calculating the changes in spectral intensity of the propagating mode and the results show that the intensity spectra correspond exactly to the infrared spectra of these molecules. This may open an effective avenue to design sensors for detecting nanometric-size molecules in the terahertz and infrared regimes.
由于石墨烯具有可调节的电子特性，并且能在红外和太赫兹频率范围内有效激发表面等离子体激元，对石墨烯的研究已引起了广泛关注。在此，我们证明了单层石墨烯带可激发涂覆石墨烯的介质纳米线（GNW）波导中的等离子体激元模式。此外，通过调节石墨烯的化学势，GNW的横向共振频谱可灵活调谐，且共振峰的幅度随分析物介电常数的虚部呈线性变化。因此，GNW可作为捕获分子光谱的探针。通过计算传播模式的光谱强度变化，展示了对甲苯、乙醇和二氧化硫薄层的宽带传感，结果表明强度光谱与这些分子的红外光谱精确对应。这可能为设计用于在太赫兹和红外波段检测纳米尺寸分子的传感器开辟一条有效途径。
