Role of surface plasmons in the optical interaction in metallic gratings with narrow slits

Abstract

We report an experimental study of the transmission of light through narrow slits in metallic gratings (Ag layer thickness of 100–400 nm, grating period of 370 or 780 nm, and slit width of 30–100 nm). Peak transmission of ∼60% is observed for TM polarization at a wavelength redshifted from the point of surface plasmon (SP) resonance at the metal/substrate interface. At the transmission minima, the angular dependence of reflection shows a sharp peak with minimum loss of optical power. Two types of surface plasmon excitation are found responsible for the observed transmission dips: (1) the SP resonance along the planes that comprise either the metal/air or metal/substrate interfaces and (2) the SP resonance localized along the surface that encloses each metal island separated by slits.

Enhancing one dimensional sensitivity with plasmonic coupling

“…Since structures can be tuned to excite plasmons when very specific conditions are met, one common use of plasmons is for nanoscale sensing of biological materials [1], [2]. Plasmons have also been used as sensors for material properties [3][4][5], as part of an alternative lithography method [6], and to boost performance of existing devices [7], [8].…”

Thermal tuning of surface plasmon resonance: Ag gratings on barium strontium titanate thin films

“…However, there is a lack of experimental investigations for thermal tuning of SPR in 1D or 2D metal/dielectric structures. This might be partially ascribed to the relative difficulty in obtaining sub-wavelength metal patterns, especially in the visible range [6]. VO 2 is very commonly used for SP thermal tuning investigations [4,5,7], due to the large variation of refractive index (∼2.8 at room temperature and ∼2.2 at 80°C at 600 nm [8]) induced by the metal-insulator phase transition around 65°C.…”

Electromagnetic Waves Propagation Characteristics in Superconducting Photonic Crystals

“…For example, the optical transmission through a nanoslit collection structure shaped on a metal layer with thin film thickness was analyzed in Refs. [10,11]. The photonic band structures of a square lattice array of metal or semiconductor cylinders, and of an array of metal or semiconductor spheres, were enumerated numerically in Ref.…”