Interaction of angular momentum carrying optical beams with a single nanowire

Abstract

Angular momentum AM is an inherent property of electromagnetic fields A lightbeam can possess both spin angular momentum SAM and orbital angular momentum OAM SAM and OAM are results of transverse spin and orbital energy momentumflows of the light beam respectively Transverse spin momentum flow originates fromthe rotating electric field vector of a circularly polarized light beam SAM can have twoorthogonal states corresponding to left and right handedness of circular polarization On the other hand transverse orbital momentum flow is a result of the azimuthal phasegradient present in optical vortex beams Systematic control of the spatial phase of avortex beam can result in an infinite number of orthogonal states of OAM AM carryingbeams can be easily generated in the laboratory by engineering polarization and spatialphase of the Gaussian output of a LASER source One of the commonly used and easyto prepare OAM carrying beams is Laguerre Gaussian LG beam AM of the lightbeam has been utilized as an extra degree of freedom to enhance optical informationtransfer Interaction of AM carrying light beams with matter not only provides a fundamentalunderstanding of light matter interaction but has been harnessed in applicationssuch as quantum memory gadgets optical trapping directional coupling and more Theeffects of optical AM interaction with matter are small at large scale and can be neglected But it is important to consider them at scales comparable to the wavelength ofthe light beam and has been utilized in nanophotonics based applications Herein we have studied the interaction of AM carrying beams with a single plasmonicnanowire NW Our study aims at how transverse spin and orbital momentumflows control the scattering of AM carrying beams from an individual NW and generationof plasmons in the NW We show the optical Spin Hall effect in the scatteringof a light beam newline newline