2020/03/04 by Kenneth L. Schepler, Мurat Yessenov, Schepler, Kenneth L. +5 · 1 citation
Engineering · Physics and Astronomy · #Plasmonic and Surface Plasmon Research #Photonic Crystals and Applications #Photonic and Optical Devices
paper · pdf · doi:10.48550/arxiv.2003.02105
We introduce the unique class of propagation-invariant surface plasmon\npolaritons (SPPs) representing pulsed surface wave packets propagating along\nunpatterned metal-dielectric interfaces and are localized in all dimensions -\nwith potentially subwavelength transverse spatial widths. The characteristic\nfeatures of such linear diffraction-free, dispersion-free `plasmonic bullets'\nstem from tight spatio-temporal correlations incorporated into the SPP spectral\nsupport domain, and we thus call them `space-time' SPPs. We show that the group\nvelocity of space-time SPP wave packets can be readily tuned to subluminal,\nsuperluminal, and even negative values by tailoring the spatio-temporal field\nstructure independently of any material properties. We present an analytical\nframework and numerical simulations for the propagation of space-time SPPs in\ncomparison with traditional pulsed SPPs whose spatial and temporal degrees of\nfreedom are separable, thereby verifying the propagation-invariance of the\nformer.\n