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We present a comprehensive investigation of resonant all-dielectric multi-layers. We first introduce a numerical as well as analytical optimization based on admittance recurrence law. We then address the technological aspects of the fabrication using dual-ion-beam sputter deposition. Using the optimally fabricated structures, we carry out experiments to optically characterize their responses in the near and far fields. Previously, our optimization strategy had been based on maximizing the absorption within the dielectric stack [1] for any illumination conditions without altering the field enhancement. Recently, we have improved this process by introducing a single zero-admittance layer that allows defining the field enhancement localization within the multi-layer [2]. Similarly to the Kretschmann configuration for surface plasmon resonances (SPR), these resonant all-dielectric components work under total internal reflection but they can support field enhancements up to 104-105. From a theoretical point of view, the enhancement is not intrinsically limited (except for nonlinear phenomena or material damages under high flux), and it is therefore the illumination bandwidths (angular divergence and spectral range), which mainly limit the resulting field enhancement [3]. We will introduce the resonant all-dielectric components, demonstrate their potential for sensing applications and give a brief comparison with SPR [4].
The authors acknowledge the PSA group for financial support of this work, the ANRT for their support through the CIFRE program and the RCMO Group of the Institut Fresnel for the realization of the coatings. This work is part of the OpenLab PSA/AMU: Automotive Motion Lab through the StelLab network.
1- Appl. Phys. Lett. 103, 131102 (2013)
2- Phys. Rev. A 97, 023819 (2018)
3- Opt. Express 25, 14883 (2017)
4- Appl. Phys. Lett. 111, 011107 (2017)
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