Bandwidths limitations of giant optical field enhancements in dielectric multi-layers

Abstract

Dielectric multilayers, when properly optimized, have been shown to sustain giant optical field enhancement directly linked to the imaginary index of the materials. Such giant optical field is of great interests to increase tremendously the sensitivity of optoelectronic systems. Unfortunately, this ultra-sensitive system is also highly depending on the illumination conditions. We discuss here the effect of the angular divergence and the spectral bandwidth of the incident laser beam on the absorption and field enhancement. In this study, we clearly show that giant optical field enhancements, up to several decades, may be achievable when the incident conditions are down few μrad and pm in term of angular and spectral bandwidths respectively.

Sensitivity of resonance properties of all-dielectric multilayers driven by statistical fluctuations

“…This can be seen from Fig. 1, which summarizes our previous results [57] using three DMs designed for a field enhancement factor of F = |E| 2 /|E 0 | 2 = 10 5 , 10 4 , 10 3 , where E 0 and E are the incident and the corresponding resulting field at the free interface, respectively. From these results one may conclude that for F >10 4 , we have to control the divergence to a precision that is currently not realizable.…”

“…The presented study of the illumination bandwidths in [57] facilitates the determination of the effects of fabrication errors impacting the optical thicknesses and thus the optical response of resonant dielectric multilayers. The considered ranges of bias, random, and combined errors in the system parameters of refractive index and physical thicknesses provided a reasonable analysis domain useful for experimental design.…”

“…Dielectric multilayers have been optimized for sustaining field enhancement factor F of 10 5 (red), 10 4 (grey) and 10 3 (blue). The hatched regions mark the experimental regions currently not achievable, for more details refer to[57]. (c) Scheme of a resonant dielectric multilayer under total internal reflection illumination with the absorbing and adaptative layers and the Bragg mirror.…”

Excitation of Bloch Surface Waves in Zero-Admittance Multilayers for High-Sensitivity Sensor Applications

“…Intrinsic factors are nonlinearities and damage thresholds, and (even slight) absorption and scattering. Extrinsic factors are related to the incident illumination band passes (in divergence and wavelength) [54], and the accuracy of the multilayer design [1,34]. Such limitations were previously analyzed [34][35][36][37][38][39][40][41][42][43][44][45][46][47] in detail since they require a compromise leading to a limited number of layers, and a realistic enhancement around four decades.…”

Micro-cavity optimization for ultra-sensitive all-dielectric optical sensors

“…Within the field of optical sensors [1][2][3][4], significant progress has been made over the last few years, drawing in particular on studies of the processes of giant enhancement of the electromagnetic field [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Among the various methods that create these enhancements, all-dielectric planar optical multilayers [20][21][22][23][24] play an essential role because they provide a large number of degrees of freedom for optimizing the design of optical enhancement.…”