Surface vector plasmonic lattice solitons in semi-infinite graphene-pair arrays.

Zhouqing Wang,Hua Long,Bing Wang,Kai Wang,Peixiang Lu

doi:10.1364/oe.25.020708

Abstract

We investigate the surface vector plasmonic lattice solitons (PLSs) in semi-infinite graphene-pair arrays (GPAs). The surface vector PLSs are composed of two components which are associated with different band gaps. Both components undergo mutual self-trapping at the boundary of the semi-infinite structure when the self-focusing nonlinearity of graphene and the light diffraction reach a balance. Thanks to the strong confinement of SPPs, the surface vector PLSs can be squeezed into a deep-subwavelength width of ~0.003λ. By comparing with bulk solitons, the surface PLSs are more readily to excite by external waves and more sensitive to the surrounding environment. The study may develop promising applications in all-optical switching devices and optical sensors on deep-subwavelength scale.

Highlights

Graphene, a single monolayer of carbon atoms arranged in 2D honeycomb lattice, has attracted much attention with its unique features in electronics and optics [1,2,3,4,5]
According to the previous works [23,28,29,30], we can predict that the semi-infinite graphene-pair arrays could support surface vector plasmonic lattice solitons (PLSs) with the components associated with different band gaps
The surface vector PLSs are composed of two components belonging to different band gaps with different frequencies

Summary

Introduction

A single monolayer of carbon atoms arranged in 2D honeycomb lattice, has attracted much attention with its unique features in electronics and optics [1,2,3,4,5]. Plasmonic lattice solitons in the infinite GSAs have been investigated, including scalar PLSs in monolayer graphene sheet arrays [23,28] and vector PLSs in graphene-pair arrays [29]. According to the previous works [23,28,29,30], we can predict that the semi-infinite graphene-pair arrays could support surface vector PLSs with the components associated with different band gaps. The surface vector PLSs are composed of two components belonging to different band gaps with different frequencies When both light components excite the self-focusing nonlinearity of graphene at the interface to balance their respective diffraction into the arrays, the surface vector PLS is formed with both components propagating stably. By changing the chemical potential of graphene, the threshold power can be modulated flexibly

Transverse distribution and propagation of surface vector PLSs

Conclusions