title: Role of hybrid wave in electromagnetic enhancement by a metallic groove doublet.
abstract: We provide an elaborate investigation on the role of a hybrid wave (HW) in electromagnetic enhancement by a groove doublet in metallic substrate. A simple HW model is built to explore the detailed effect of HW on electromagnetic enhancement. The effective range of electromagnetic enhancement is obtained within 0.1λ away from a metal surface. The excitation of HW by a single groove has a gentle growth (from 0.03 to 0.26) as the groove gets wide, which implies that the emerging field of HW launched by a single groove is quite weak for narrow ones. HW, being like an "energy porter," takes away partial energy from the Fabry-Perot resonance, which will be further coupled into the fundamental mode in the other groove after traveling along the metal surface. Our analysis reveals a compensation of electromagnetic enhancement for wide grooves attributed to the appearance of HW. The dependence of HW and electromagnetic enhancement on the noble metal type is also discussed.
authors: Siwen
authors: S
authors: Zhang
authors: Haitao
authors: H
authors: Liu
authors: Xiaodong
authors: X
authors: Sun