Experimental demonstration of two-dimensional hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

Guanghui Ren,Kyle J Berean,Arnan Mitchell,Joachim M Hamm,Thach G Nguyen,Iryna Khodasevych,Didit Yudistira,Steffen Schoenhardt,Ortwin Hess

doi:10.1063/1.4995996

Abstract

Nanoscale plasmonic structures can offer unique functionality due to extreme sub-wavelength optical confinement, but the realization of complex plasmonic circuits is hampered by high propagation losses. Hybrid approaches can potentially overcome this limitation, but only few practical approaches based on either single or few element arrays of nanoantennas on dielectric nanowire have been experimentally demonstrated. In this paper, we demonstrate a two dimensional hybrid photonic plasmonic crystal interfaced with a standard silicon photonic platform. Off resonance, we observe low loss propagation through our structure, while on resonance we observe strong propagation suppression and intense concentration of light into a dense lattice of nanoscale hot-spots on the surface providing clear evidence of a hybrid photonic plasmonic crystal bandgap. This fully integrated approach is compatible with established silicon-on-insulator (SOI) fabrication techniques and constitutes a significant step toward harnessing plasmonic functionality within SOI photonic circuits.

Highlights

Surface plasmons[1] are coherent oscillations of electrons at metal-dielectric interfaces that can exist either in propagating or in localized forms, i.e., surface plasmon polaritons (SPPs) and localized surface plasmon resonances (LSPRs)
Luo[19] realized nanofocusing in a hybrid plasmonic photonic nanotaper structure. Each of these demonstrations interfaces to a single element or short one dimensional chains of elements, providing limited opportunity for sophisticated photonics such as bandgap engineering and electromagnetic crystal structures which have been so successful in dielectric photonics, for intense concentration of light combined with dispersion engineering leading to enormous enhancements in nonlinearity.[23,24]
Using transmission scanning near field optical microscopy (Tra-SNOM)[26,27] to directly and simultaneously measure the nanogap tilings, we find that the optical fields concentrate in the sub-wavelength gaps of the nanoplasmonic surface tiling

Summary

Introduction

Surface plasmons[1] are coherent oscillations of electrons at metal-dielectric interfaces that can exist either in propagating or in localized forms, i.e., surface plasmon polaritons (SPPs) and localized surface plasmon resonances (LSPRs). By using the proposed hybrid plasmonic waveguides, Fevrier[17] and Apuzzo[18] experimentally realized a hybrid integration of gold nano-particles chain on silicon chip and characterized their interactions among each element through near field scanning, respectively.

Results

Conclusion