各向异性特异材料波导中表面等离子体的共振性质

使用时域有限差分法,研究了各向异性特异材料(AMM)作为包层的AMM/介质/AMM波导中表面等离子体的共振性质.色散关系表明,当特异材料为负磁导率的always-cutoff型时,AMM/介质/AMM波导支持TE极化的表面等离子体,表面等离子体的波长随着中间介质层的厚度和特异材料磁等离子体频率的减小而变短.在有限长度AMM/介质/AMM波导中,由于两端界面的反射,表面等离子体模在波导中形成Fabry-Perot共振,而实现亚波长的表面等离子体微腔.在共振频率,电场强度在微腔的中部达到最大值,而磁场分别在两端界面处达到最大,电磁能强局域在中间介质层中,这一性质将在可调的具有强局域特性的亚波长微腔及腔量子电动力学中具有潜在的应用.

Resonance properties of surface plasmon in the anisotropic metamaterial waveguide

The resonance properties of surface plasmon in the AMM/dielectric/AMM waveguide are theoretically studied by using the finite-difference time-domain technique, where the claddings are anisotropic metamaterial (AMM) . From the dispersion relation, it is found that the AMM/dielectric/AMM waveguide supports TE polarized surface plasmon if AMM is always-cutoff with negative permeability. The wavelength of the surface plasmon becomes shorter when both the thickness of the dielectric core and the magnetic plasma frequency of AMM decrease. For an AMM/dielectric/AMM waveguide with a finite length, a subwavelength plasmon microcavity can be formed by Fabry-Perot resonance caused by the reflection of the guided mode at the entrance and the exit surfaces. At the resonant frequency, the electric field is maximized in the center, the magnetic field is maximized at the dielectric core entrance and exit, and the electromagnetic energy is strongly concentrated around the dielectric core. Such electromagnetic properties will have potential applications in the tunable subwavelength microcavity with strongly localized field and in the cavity quantum electrodynamics.