论文部分内容阅读
设计了一种领结形中空表面等离子体波导.采用频域有限差分法,对这种波导所支持的基模的能流密度分布、有效折射率、传播长度和模式面积随几何结构参数和工作波长的依赖关系进行了分析.结果表明,沿纵向的能流主要分布在两个上下突起所形成的中间区域.通过调整几何参数及工作波长,可以调节模式的有效折射率、传播长度和模式面积.在工作波长确定的条件下,有效折射率随突起半径的增大呈减小趋势,而传播长度和模式面积则随着突起半径的增大呈增大趋势,四个角上的圆弧半径对波导的传输特性有微调作用,左右扇形区域的半径对波导的传输特性有较明显的调节作用.在几何参数确定的条件下,相对于工作波长705.0nm的情形来说,工作波长较大时,场的分布范围较大,场与金属表面的接触面积较大,场与金属银的相互作用较弱,有效折射率就较小,传播距离也就较长.最后,讨论了这种中空表面等离子体波导在传感器领域应用的可能性.
A kind of bow-tie hollow surface plasmon waveguide is designed.The energy density distribution, effective refractive index, propagation length and mode area of the fundamental mode supported by this waveguide are changed with the geometrical parameters and working wavelength The results show that the energy flow in the longitudinal direction is mainly distributed in the middle region formed by two upper and lower protrusions.The effective refractive index, propagation length and mode area of the mode can be adjusted by adjusting the geometric parameters and working wavelength. Under the conditions of the working wavelength, the effective refractive index decreases with the increase of the projection radius, while the propagation length and the pattern area increase with the increase of the projection radius. The arc radius at the four corners Waveguide transmission characteristics of fine-tuning effect, the radius of the left and right sector of the waveguide transmission characteristics have a more obvious regulation.Under the conditions of the geometric parameters, relative to the working wavelength 705.0nm case, when the operating wavelength is large, The field has a wide range of distribution, the contact area between the field and the metal surface is larger, the interaction between the field and the metal silver is weak, the effective refractive index is smaller, and the propagation distance It is longer. Finally, we discuss the possibility of such a hollow waveguide surface plasmon sensor in the applied field.