Lectric-field distributions of dielectric single layers of spheres with different compactness

Abstract

The internal electric-field distribution from single layers of dielectric spheres with high refractive index (n = 2:65) has been analyzed for a number of different compactness cases by FDTD (Finite- Difference Time-Domain) method. The field distributions from the transmission spectra were compared with the internal electric-field distribution of the Mie modes of an isolated sphere. In general, the agreement is very good in almost all cases studied. The results show that TE and TM Mie modes are the origin of the resonances in the transmission spectra of the single layers. The resonances of the monolayer attributed to TE11 and TM11 Mie modes are only excited for compactness values lower than 0.38, suggesting a dependence of periodical arrangement effects for these modes. Moreover, the field distribution corresponding to some of the dips in the spectrum cannot be directly attributed to Mie modes (TE21). The result indicates these are formed by degenerated or weakly coupled Mie modes induced by the periodic structure.