Nanoscale light confinement and transport in symmetric hybrid plasmonic waveguides based on silicon nanoslots

<正>Light confinement at the nanoscale beyond the fundamental diffraction limit is of critical importance to the advancement of next-generation photonic technology,since it offers unprecedented opportunities with dramatically enhanced light-matter interactions.A silicon-nanoslot based symmetric hybrid structure was reported,capable of providing low propagation loss,subwavelength mode size and tight field confinement inside the low-index gap region.The nice optical performance in conjunction with several unique features could enable a number of further applications.In addition to the waveguide proposed here,a number of alternative guiding schemes could also be employed to achieve the goal of propagation loss reduction with subwavelength mode confinement,including structures based on horizontal slot waveguides,and many other configurations capable of forming symmetric or near-symmetric environment along with high-index contrast near the metallic waveguides,such as metal nanostructures covered by low-high-index dielectrics supported by low-index substrates,and coaxial type-structures consisting of metallic nanowires surrounded by dielectrics.