Extreme optical chirality of plasmonic nanohole arrays due to chiral Fano resonance

Kondratov, A. V.; Gorkunov, M. V.; Darinskii, A.N.; Гайнутдинов, Р. В.; Rogov, Oleg Y.; Ezhov, A. A.; Артемов, В. В.

doi:10.1103/physrevb.93.195418

Cited by 59 publications

(49 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, chiroptical responses were studied in simple 1D metal grooves [33] and nanohole arrays [34]. Most of the chiral nanostructure fabrication involves sophisticated, challenging and expensive techniques; however, authors in [35][36][37] showed that complex chiral shapes can be produced in silver films by a conventional single-pass focused ion beam technique.…”

Section: Introductionmentioning

confidence: 99%

Circular Dichroism in Low-Cost Plasmonics: 2D Arrays of Nanoholes in Silver

et al. 2020

View full text Add to dashboard Cite

Arrays of nanoholes in metal are important plasmonic devices, proposed for applications spanning from biosensing to communications. In this work, we show that in such arrays the symmetry can be broken by means of the elliptical shape of the nanoholes, combined with the in-plane tilt of the ellipse axes away from the array symmetry lines. The array then differently interacts with circular polarizations of opposite handedness at normal incidence, i.e., it becomes intrinsically chiral. The measure of this difference is called circular dichroism (CD). The nanosphere lithography combined with tilted silver evaporation was employed as a low-cost fabrication technique. In this paper, we demonstrate intrinsic chirality and CD by measuring the extinction in the near-infrared range. We further employ numerical analysis to visualize the circular polarization coupling with the nanostructure. We find a good agreement between simulations and the experiment, meaning that the optimization can be used to further increase CD.

show abstract

Section: Introductionmentioning

confidence: 99%

Circular Dichroism in Low-Cost Plasmonics: 2D Arrays of Nanoholes in Silver

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Symmetry aspects are of key importance for the design of chiral metasurfaces. While the chirality by itself requires the absence of mirror symmetry planes, rotational axes of the order of 3 and higher ensure that circularly polarized waves are the true eigenmodes and all polarization transformations during the transmission of normally incident light are caused by the metasurface chirality 42 .…”

Section: Resultsmentioning

confidence: 99%

“…From the symmetry point of view, for the normally incident light, the optical properties of a chiral 4-fold rotationally symmetric metasurface are identical to those of a layer of isotropic chiral medium 42 . The corresponding key optical chirality parameters–circular dichroism (CD) and optical activity (OA)–can be resolved by different methods, and are independent of the sample orientation with respect to the incident linear polarization as well as, due to the Lorentz reciprocity, of the side of incidence 37 .…”

Section: Resultsmentioning

confidence: 99%

Chiral visible light metasurface patterned in monocrystalline silicon by focused ion beam

Gorkunov

Rogov

Kondratov

et al. 2018

Sci Rep

View full text Add to dashboard Cite

High refractive index makes silicon the optimal platform for dielectric metasurfaces capable of versatile control of light. Among various silicon modifications, its monocrystalline form has the weakest visible light absorption but requires a careful choice of the fabrication technique to avoid damage, contamination or amorphization. Presently prevailing chemical etching can shape thin silicon layers into two-dimensional patterns consisting of strips and posts with vertical walls and equal height. Here, the possibility to create silicon nanostructure of truly tree-dimensional shape by means of the focused ion beam lithography is explored, and a 300 nm thin film of monocrystalline epitaxial silicon on sapphire is patterned with a chiral nanoscale relief. It is demonstrated that exposing silicon to the ion beam causes a substantial drop of the visible transparency, which, however, is completely restored by annealing with oxidation of the damaged surface layer. As a result, the fabricated chiral metasurface combines high (50–80%) transmittance with the circular dichroism of up to 0.5 and the optical activity of up to 20° in the visible range. Being also remarkably durable, it possesses crystal-grade hardness, heat resistance up to 1000 °C and the inertness of glass.

show abstract

“…Usage of the data obtained with the vertical probe leads to a rather sloping relief (figure 9a). Though we successfully used this model for the experimental results reproduction 14 , we had to pierce it artificially by a cylinder to make it look more similar to the original structure. The 3D model obtained with the tilted probe combined with the appropriate post-processing routine looks better compared to the one investigated by a vertical probe (figure 9b).…”

Section: Discussionmentioning

confidence: 99%