Porous Silicon Bragg Reflector and 2D Gold-Polymer Nanograting: A Route Towards a Hybrid Optoplasmonic Platform.

Paola Pellacani,Vicente Torres-Costa,Franco Marabelli,Miguel Manso Silvàn,Chloé Rodriguez,Lucia Fornasari

doi:10.3390/nano9071017

Paola Pellacani, Vicente Torres-Costa + Show 4 more

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https://doi.org/10.3390/nano9071017

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Abstract

Photonic and plasmonic systems have been intensively studied as an effective means to modify and enhance the electromagnetic field. In recent years hybrid plasmonic–photonic systems have been investigated as a promising solution for enhancing light-matter interaction. In the present work we present a hybrid structure obtained by growing a plasmonic 2D nanograting on top of a porous silicon distributed Bragg reflector. Particular attention has been devoted to the morphological characterization of these systems. Electron microscopy images allowed us to determine the geometrical parameters of the structure. The matching of the optical response of both components has been studied. Results indicate an interaction between the plasmonic and the photonic parts of the system, which results in a localization of the electric field profile.

Highlights

The fascinating properties of photonic and plasmonic systems have served as ingredients in many different fields where an improvement of the light manipulation efficiency is required, such as in photovoltaic cells and biochemical sensing devices.Metal-dielectric interfaces are known to guide Surface Plasmon–Polariton (SPP) modes, while nanometric metallic structures support Localized Surface Plasmons (LSPs)
In the present work we present a hybrid structure obtained by growing a plasmonic 2D nanograting on top of a porous silicon distributed Bragg reflector
The recent and rapid development of research in this area was catalysed when scientists realized that SPP and LSP modes may lead to the localization of guided light signals far beyond the diffraction limit for electromagnetic waves in dielectric media

Summary

Introduction

The fascinating properties of photonic and plasmonic systems have served as ingredients in many different fields where an improvement of the light manipulation efficiency is required, such as in photovoltaic cells and biochemical sensing devices. The basic idea is to bridge the plasmonic and photonic world in order to combine the low mode volume of plasmonics with high Q factor of photonics to produce high local field enhancement compared to the split optical structures This kind of systems is a promising solution for tailoring the light-matter coupling [44,45,46], for enhancing the magneto-optic activity [47], for modifying the spontaneous emission [48,49,50] and for sensing application [51,52,53]. We have fabricated and characterized in terms of surface morphology and optical response the individual structures (DBR and plasmonic nanograting or plasmonic cavity crystal, PLC), as well as the hybrid system

Preparation of Porous Silicon Photonic Crystals

Hybrid Plasmonic–Photonic Structure

Conclusions