论文期刊

Extraordinary optical diffraction from hole pair based on near-field optical thin-microcavity theory




作者: Xu Chen, Jiu Hui Wu, Pei Cao
发表/完成日期: 2018-07-04
期刊名称: Journal of Optics
期卷: Vol.20
相关文章: Extraordinary optical diffraction from hole pair based on near-field optical thin-microcavity theory.pdf   
论文简介
To realize optical coupling between various nanostructured elements and nanoscale field
confinement, a fundamental model of the near-field diffraction from a subwavelength hole pair
within a conducting thin film is derived theoretically. Coupling effects between these two holes
are investigated in detail using the near-field optical thin microcavity theory and the coupledmode method, and the results are then verified via finite element simulations. Some extraordinary
diffraction phenomena are found and are attributed to the following two coupling mechanisms:
(1) the edge effect from the thin microcavity theory that occurs at each hole edge when an
incident electric field illuminates the upper surface of the thin film; and (2) the enhanced in-plane
electromagnetic waves that propagate along the two film surfaces and interact with each other in
the vicinity of the holes. Analysis of the effects of the structural parameters on the transmittance
shows that the coupling effect can be enhanced or attenuated by the interference conditions,
depending on the incident wavelength and the phase difference determined by the hole–hole
distance. The extraordinary diffraction effects presented here have potential for applications in
near-field optical devices.