太赫兹表面等离激元共振传感器

对通过棱镜耦合的太赫兹表面等离激元共振传感器的工作特性进行了理论分析.此类器件在可见光波段工作时,在由样品折射率、金属膜层性质和厚度决定的共振角度下会出现一个反射极小峰;但工作在太赫兹频率时,表面等离激元共振现象表现为一个反射增强的尖峰,而且这一共振角度与棱镜和样品的折射率之间存在一个简单的对应关系,并不依赖于棱镜所镀...

Surface plasmon resonance sensor working at terahertz frequency

The authors provided an analysis of the surface plasmon resonance sensor (SPRS) working at terahertz (THz) frequency with angular modulation and made a brief comparison between optical SPRS and THz-SPRS. At optical frequency, there is a dip in the angular reflection spectrum due to the resonant transfer of the energy carried by the incident light wave to surface plasmon, while there is an enhanced reflection peak at the terahertz frequency. The position of the peak is solely determined by the refractive indices of the prism and the sample, and independent of the properties of the metal film. Our results show that the determination of the dielectric constant of a sample in the THz SPRS is much simpler than its optical counterpart. Taking into account of the importance of THz technology applying in biological and medical field, the authors' device may provide a valuable method for bio-sensing and analysis.