Campione Salvatore, Kim Iltai, de Ceglia Domenico, Keeler Gordon A, Luk Ting S
Opt Express. 2016 Aug 8;24(16):18782-9. doi: 10.1364/OE.24.018782.
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.
我们研究了玻璃上亚波长厚度的简并掺杂半导体纳米层（如铟锡氧化物）在近零介电常数（ENZ）区域所支持的光学极化激元模式。通过转移矩阵法和复频率/实波数分析，对辐射（R，在光线左侧）和非辐射（NR，在光线右侧）ENZ极化激元模式的色散进行了实验测量和理论分析，二者结果吻合度很高。我们利用Kretschmann结构，在接近NR-ENZ极化激元模式色散的入射条件下，观测到了定向的近完美吸收。伴随场增强效应，这为我们提供了一条尚未探索的途径，可用于增强非线性光学过程，并为超快、可调谐热发射开辟新方向。
