Electromagnetic field enhancement in Bloch surface waves

Abstract

We present a systematic comparison between guided modes supported by slab waveguides and Bloch Surface Waves (BSWs) propagating at the surface of truncated periodic multilayers. We show that, contrary to common belief, the best surface field enhancement achievable for guided modes in a slab waveguide is comparable to that observed for BSWs. At the same time, we demonstrate that, if one is interested in maximizing the electromagnetic energy density at a generic point of a dielectric planar structure, BSWs are often preferable to modes in which light is confined uniquely by total internal reflection. Since these results are wavelength independent and have been obtained by considering a very wide range of refractive indices of the structure constituent materials, we believe they can prove helpful in the design of future structures for the control and the enhancement of the light-matter interaction.

One-dimensional photonic crystal for Bloch surface waves and radiation modes-based sensing

“…7(a), extrema due to the response of guided modes in the multilayer system and resonance dips are obtained, and they are shifted toward longer wavelengths as the angle of incidence decreases. In addition, the resonances with the maximum depth are due to light irradiation from the structure into the analyte (water) and are affected by optical field enhancement in the structure [40]. In other words, the reflectance decreases to 0…”

Hybrid Confinement of Visible Light in a Nanophotonic Resonator

“…Bloch surface waves (BSWs) propagating at the truncation interface of a periodic multilayer are a valuable approach for surface optics, with surface field enhancements larger than those achievable in dielectric slabs [2]. BSWs provide large freedom in terms of constituent materials, from organic compounds to semiconductors, and operate in a wide spectral range, remarkably at visible wavelengths, for which there is paucity of transparent materials having a strong refractive index contrast.…”

Surface electromagnetic waves in anisotropic superlattices

“…For instance, a bilayered superlattice composed of isotropic materials allows a simple explicit expression of the transfer matrix and hence of the reflection and refraction coefficients as well as of the dispersion equation for surface waves (see [15,16]). Within the above framework, explicit calculations have proved fruitful for studying different aspects of the SEW propagation in half-infinite superlattices under different boundary conditions [15][16][17][18][19][20][21][22], in finite superlattices on a substrate [23,24], and in quasiperiodic [25,26] and functionally graded [27][28][29] superlattices. At the same time, it is well known that the SEW dispersion equation even for the simplest setups is a transcendental one, i.e., it does not admit a closed-form solution, and, moreover, its formulation for more general cases of anisotropic superlattices with a complex arrangement of unit cells (period) is virtually implicit.…”