Long-range propagation of surface plasmons in a thin metallic film deposited on an anisotropic photonic crystal

Abstract

We propose using a strongly anisotropic dielectric as a substrate for plasmonic devices. We show that the propagation range of surface plasmons is increased if the substrate is a birefringent dielectric crystal with a properly oriented optical axis. The increase of the propagation range depends on the degree of anisotropy, and, consequently, it turns out to be small for substrates of natural optical crystals, where anisotropy is weak. However, in specially designed photonic crystals, the anisotropy may be very strong, thus leading to appreciable increase of the propagation range. A photonic-crystal substrate, being a medium with nonlinear dispersion, also affects the dispersion law of the surface plasmon. All these effects may increase the efficiency of modern plasmonic and optoelectronic devices.

Long-range surface plasmons in dielectric-metal-dielectric structure with highly anisotropic substrates

“…The effects of anisotropy may lead to further increase in the propagation length. Indeed, we report about 20-fold increase in the propagation length of long-range surface plasmon in the symmetric configuration when compared to that of the asymmetric ͑vacuum-metal-dielectric͒ one 13 for the same given parameters at = 1.57 m. It is important to mention at this point that an attempt to study the effects of anisotropy on the propagation length was made in Ref. 14.…”

“…13 For instance, L͑͒Ϸ2.3 mm at = 1.57 m for perpendicular orientation in the case of symmetric configuration compared to L͑͒Ϸ100 m at = 1.57 m for the same orientation for asymmetric configuration. That is an enhancement of propagation length by more than 20 times.…”

“…In Ref. 13, the proposed substrate was two-dimensional ͑2D͒ photonic crystal ͑a periodic arrangement of parallel cylinders͒ and in Ref. 12, the metallic film was deposited on multilayered dielectric heterostructure ͓one-dimensional ͑1D͒ photonic crystal͔.…”

Surface electromagnetic waves: A review

“…SPP-wave experiments are commonly used to measure the constitutive properties of nematic liquid crystals [81][82][83][84]. Anisotropic dielectric partnering materials realizable as periodic stacks of electrically thin layers [85] have also been suggested [86] in the present context.…”

Index of refraction of a photonic crystal of carbon nanotubes and homogenization of optically anisotropic periodic composites

“…Since it is a surface wave with very low energy losses, the Dyakonov wave may replace surface plasmons in the near-field optics and integrated photonic circuits. At the same time application of optically anisotropic substrates leads to essential increase of the propagation length of surface plasmons, thus, giving rise to higher efficiency of plasmonic devices [39]. These and other examples show that dielectric materials with high optical anisotropy is on demand in modern optoelectronics.…”