Plasmonic control of extraordinary optical transmission in the infrared regime. (14th November 2016)

• Record Type: Journal Article
• Authors: Sangiao, S; Freire, F; de León-Pérez, F; Rodrigo, S G; De Teresa, J M
• Is Part Of: Nanotechnology. Volume 27:Number 50(2016)
• Publication Date: 2016-11-14
• Subjects: hole arrays -- surface plasmon polaritons -- enhanced transmission -- subwavelength apertures; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/50/505202
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We demonstrate that the spectral location of extraordinary optical transmission (EOT) resonances in metallic arrays of rectangular holes can be plasmonically tuned in the near and mid-infrared ranges. The experiments have been performed on patterned gold films. We focus on a subset of localized resonances occurring close to the cut-off wavelength of the holes, λ c . Metals are usually regarded as perfect electric conductors in the infrared regime, with an EOT cut-off resonance found around λ c = 2 L for rectangular holes ( L being the long edge). For real metals, the penetration of the electromagnetic fields is simply seen as effectively enlarging L . However, by changing the hole short edge, we have found that λ c varies due to the excitation of gap surface plasmon polaritons. Finite-element calculations confirm that in these high aspect ratio rectangles with short edges two important aspects have to be taken into account in order to explain the experiments: the finite conductivity of the metal and the excitation of gap-surface plasmons inside the nanoholes.