title: Experimental verification of epsilon-near-zero plasmon polariton modes in degenerately doped semiconductor nanolayers.
abstract: We investigate optical polariton modes supported by subwavelength-thick degenerately doped semiconductor nanolayers (e.g. indium tin oxide) on glass in the epsilon-near-zero (ENZ) regime. The dispersions of the radiative (R, on the left of the light line) and non-radiative (NR, on the right of the light line) ENZ polariton modes are experimentally measured and theoretically analyzed through the transfer matrix method and the complex-frequency/real-wavenumber analysis, which are in remarkable agreement. We observe directional near-perfect absorption using the Kretschmann geometry for incidence conditions close to the NR-ENZ polariton mode dispersion. Along with field enhancement, this provides us with an unexplored pathway to enhance nonlinear optical processes and to open up directions for ultrafast, tunable thermal emission.
authors: Salvatore
authors: S
authors: Campione
authors: Iltai
authors: I
authors: Kim
authors: Domenico
authors: D
authors: de Ceglia
authors: Gordon A
authors: GA
authors: Keeler
authors: Ting S
authors: TS
authors: Luk