Surface plasmons enhance optical transmission through subwavelength holes

Abstract

Optically thick metal films perforated with a periodic array of subwavelength holes show exceptional transmission properties. The zero-order transmission spectra exhibit well-defined maxima and minima of which the positions are determined by the geometry of the hole array. We show that the minima are the collection of loci for Wood's anomaly, which occurs when a diffracted beam becomes tangent to the film, and that the maxima are the result of a resonant excitation of surface plasmons ͑SP's͒. SP's from both surfaces of the metal film are apparent in the dispersion diagram, independent of which side of the film is illuminated, indicating an anomalously strong coupling between the two sides. This leads to wavelength-selective transmission with efficiencies that are about 1000 times higher than that expected for subwavelength holes.

Surface plasmon mediated near-field imaging and optical addressing in nanoscience

“…SPPs scatter into transmitted propagating light after interacting with a nanohole (see Figs.9a,b). This is clearly reminiscent of Ebbesen results obtained with arrays of nanoholes Ghaemi et al, 1998) which show an enhanced transmission due to light coupling into SPPs. In the present case (see Figs.9c and d) one can map the SPP intensity on the gold surface by scanning the sample with a NSOM in the close vicinity of a given hole.…”

Light‐Driven Plasmonic Color Filters by Overlaying Photoresponsive Liquid Crystals on Gold Annular Aperture Arrays

“…Additionally, the PSPs related to the period of the annular array also play an important role for the selective transmission. The PSPinduced transmission peak can be approximately estimated as [ 46 ] where ε d and ε m are the dielectric functions of the dielectric and the metal, respectively, Λ is the lattice constant of the array, and n x and n y are integers.…”

Enhanced Design of Narrowband Filters Based on the Extraordinary Transmission Through Single Fishnet Structures

“…However, it is readily deduced that (13) in its present form is not practical, since (x 2 ) S is not known in advance. To overcome this difficulty, (7) and (8) are combined to yield…”

“…Thus, substituting (14) into (13) and plugging the outcome into (4)-(5), the enhanced relations (15) and (16), while red dash-dotted lines to the relations of [26].…”

“…During the next decade, a lot of noteworthy efforts have been conducted to reveal the underlying physics of this intriguing phenomenon [11,12]. The most prevalent interpretation has been derived from the generation of surface plasmons on metallic surfaces [13][14][15][16] due to the plasma-like behavior of metals at optical frequencies. Yet, experiments showed that the ET phenomenon occurs also at microwave frequencies [17], where metals act as perfect conductors and, therefore, cannot support surface plasmons.…”