Electrical generation of visible surface plasmon polaritons by a nanopillars antenna array

Cheng Zhang,Jean-Paul Hugonin,Benjamin Vest,Jean-Jacques Greffet,Anne-Lise Coutrot

doi:10.1063/5.0046013

Abstract

Electrical excitation of surface plasmon polaritons by inelastic tunneling electrons has been put forward as a potential nanosource that can be used in a variety of on-chip optoelectronic applications. In this article, we report a source based on an array of gold cylindrical antennas deposited on an alumina tunnel junction. This configuration has several merits: the junction can be operated under a high bias (&gt;3 V) so that surface plasmons can be emitted in the visible region at room temperature; the antenna controls the surface plasmon emission spectrum; the radiative power per unit area is enhanced by more than two orders of magnitude compared to a planar junction.

Highlights

Surface plasmon polaritons (SPPs) have shown great potential for many photonic applications in the past decades[1,2] because of their unique capability to confine electromagnetic energy both in space and time
The time scale of light emission by inelastic tunneling electrons is on the order of a few fs, paving the way toward the development of an ultrafast SPP source.[14,15]
We aim at demonstrating light emission in the visible region, which is important for many plasmonic applications, for instance, bio-sensing[31] and imaging.[32]

Summary

Introduction

Surface plasmon polaritons (SPPs) have shown great potential for many photonic applications in the past decades[1,2] because of their unique capability to confine electromagnetic energy both in space and time. Considering all these aspects in the design of the array, we use a cylindrical nanopillar antenna based MIM tunnel junction, which has the following features: (i) the junction area can be controlled around 100 × 100 nm[2], (ii) the antenna mode of a pillar antenna can enhance the field in the tunnel gap in order to couple more efficiently to the fluctuating tunnel current, and (iii) the coupling between the antenna mode and the propagating surface plasmon can be optimized.

Results

Conclusion