周期地嵌入电介质球壳的金属表层的表面等离子激元及其与电介质腔体模式的耦合  

Surface plasmon polaritons and its coupling with cavity mode in the system of dielectric spherical shells periodically mounted in a metal substrate

作　　者：郑俊娟[1] 孙刚[1] 

机构地区：[1]中国科学院物理研究所,北京100080

出　　处：《物理学报》2005年第6期2751-2757,共7页Acta Physica Sinica

摘　　要：通过观察金属底板中周期地嵌入电介质球壳的体系的光学吸收性质,研究了表面等离子激元以及与其他电磁模式的耦合特性.在这种周期结构的金属表面,发现存在两种响应频率,分别对应于表面等离子激元模式和金属中的电介质腔体模式.在这些响应频率上,可观察到与它们相对应的吸收峰.由于金属的表面模式不能与平面入射光直接耦合,而腔体模式与平面入射光和表面等离子激元模式的耦合一般较弱,因而通常情况下这些吸收峰的峰值有限.然而,通过调整体系中的某些参数,可以使腔体模式和表面模式的频率非常接近,这时二者之间的耦合强度将大大提高.此时,在相应的频率附近可观察到极强的吸收峰.详细地研究了介质球壳的物理和几何参数对此共振吸收的影响.We investigate the surface plasmon polaritons and its coupling with other electromagnetic modes by observing the absorption spectrum on a system of dielectric spherical shells periodically mounted in a metal substrate. We found that there exist two resonance frequencies in the system corresponding to surface plasmon polaritons mode and cavity mode. At these frequencies, we can find related peaks in absorbance. Since the surface plasmon polaritons cannot couple with the incident plane wave directly and both couplings of the cavity mode with the incident wave and the surface plasmon polaritons are also weak, so the strength of absorption peaks are generally very limited. However, we can adjust some parameters in the system to make the surface plasmon polaritons and the cavity mode with almost the same frequency. In this case, the coupling can be dramatically enhanced, and we can observe very strong peaks in absorbance. The relationships of resonance absorption with some physical and geometrical parameters are discussed in detail.

关 键 词：腔体模式 表面等离子体 共振吸收 光学吸收 

分 类 号：O441[理学—电磁学]