Holes with very acute angles: a new paradigm of extraordinary optical transmission through strongly localized modes

Abstract

It is shown that submicrometer holes with very acute angles present extraordinary optical transmission peaks associated to strongly localized modes. The positions of these peaks are: (i) strongly redshifted with respect to the peak position that could be expected if the considered hole were in a film made of perfect electric conductor, (ii) independent on the angle of incidence for a large range of angles and (iii) strongly dependent on the direction of the incident electric field. In addition, it is demonstrated that these properties are linked to the mechanisms leading to the existence of channel-plasmon-polaritons.

Effect of film thickness and dielectric environment on optical transmission through subwavelength holes

“…Similar results have been found in the optical regime also with rectangles in gold 21 and annular hole arrays in silver, 22 and this phenomenon is also expected to be found in triangles with acute angles. 40 Interestingly, in Fig. 8, once h ≈ 2 skin depths (∼60 nm), the resonant wavelength eventually blueshifts as a result of the typical decaying behavior due to the direct transmission through the metal films.…”

Absorption-induced transparency metamaterials in the terahertz regime

“…Although a regular lattice has been chosen because it is a robust, easier to fabricate at large scale system and that allows tight packaging, note however that AIT is determined by the guiding properties of light of a single hole when filled by the molecules, so AIT can be found in isolated holes [2,3]. Therefore, the use of different hole shapes [26][27][28] and spatial distributions of holes would provide of additional freedom to exploit AIT.…”

Extraordinary Transmission of Three-Dimensional Crescent-like Holes Arrays

“…5d, it can be found that the electric field is strongly localized at the low arc of the 3DCLH, which indicates an asymmetric localized surface plasmon resonance. Such a resonance, it could show an angle insensitive coupling to incident light similar to the symmetric localized plasmon resonance [27], this might be the reason why the peak is consistent with the change of the incident angle when the electric field of the incident beam is perpendicular to the cross-line of the 3DCLH. Therefore, we found a novel physical phenomenon of EOT whose peak position is determined by an asymmetric LSP rather than SPP.…”

“…To specify the contribution of the LSP, arrays of holes with a nanoparticle in each hole are fabricated and measured [19–22], it is found that both the SPP and the LSP contribute to the optical transmission, and both the real and imaginary parts of the polarizability of the particles which induce LSP play important roles in the transmission suppression and enhancement [20]. Very recently, an array of holes with very acute angles was found to exhibit a strong EOT effect caused by the LSP [27], an array of three-dimensional holes was also found that it has strong EOT effect induced by the LSP [28]. The waveguide mode across each hole can also play an important role in the extraordinary transmission through Fabry–Perot resonance [14, 29].…”