Controlled plasmon resonance in closed metal/insulator/metal nanocavities

Abstract

The controlled plasmon resonance in nanometer-sized optical cavities with a closed end has been demonstrated. A nanosheet plasmon cavity is a metal/insulator/metal waveguide with a finite length. Its lowest-order transverse-magnetic guided mode is reflected at the ends and exhibits the Fabry-Pérot resonance. In this study, one of the ends was closed by an obliquely evaporated Au film, and the so-called organ pipe resonances were observed as reflection dips. Since such closed configurations offer a higher field enhancement and higher detection efficiency of the scattered light, they are promising as fundamental structures for Raman enhancement.

A Metal-Insulator-Metal Deep Subwavelength Cavity Based on Cutoff Frequency Modulation

“…In the MIM waveguide, the effective index of the waveguide mode increased for thinner dielectric layers between the metal layers [24]. Therefore, as the thickness (t) of the dielectric layer increased, the dispersion curve moved upward due to the smaller effective index (caused by weaker plasmonic coupling).…”

“…For this reason, MIM waveguide-based cavities were proposed to realize compact devices with various structures, such as disks [17,18], rings [19,20], and blocks [21][22][23]. As the dielectric layer between metals becomes thinner, the propagating SPP mode has a larger k (wavevector), thereby miniaturizing the physical size of the photonic device [13,21,24]. In MIM-based devices, there are two main optical losses: the metal absorption loss and the radiation loss.…”

Dual-band near-infrared plasmonic perfect absorber assisted by strong coupling between bright-dark nanoresonators

“…Highly integrated photonics circuits have developed so fast over the past few years, and the corresponding fabrication technologies, such as electron beam lithography [28], reactive ion etching [29], magnetron sputtering technology [30], have also made much progress. It worth noting that, dating back to the year of 2006, filling dielectric into a 3-nm-width gap had been reported by using magnetron sputtering technology [30].…”

Analytical Determination of Plasmon Resonances in MIM Nanocavities

“…4a, we additionally included the results obtained from an estimation formula used in some literatures [16,17]:…”