Anopchenko Aleksei, Gurung Sudip, Bej Subhajit, Lee Ho Wai Howard
Department of Physics & Astronomy, University of California, Irvine, CA 92697, USA.
Photonics Laboratory, Physics Unit, Tampere University, Tampere, 33720, Finland.
Nanophotonics. 2023 Mar 6;12(14):2913-2920. doi: 10.1515/nanoph-2022-0816. eCollection 2023 Jul.
Using electrodynamical description of the average power absorbed by a conducting film, we present an expression for the electric-field intensity enhancement (FIE) due to epsilon-near-zero (ENZ) polariton modes. We show that FIE reaches a limit in ultrathin ENZ films inverse of second power of ENZ losses. This is illustrated in an exemplary series of aluminum-doped zinc oxide nanolayers grown by atomic layer deposition. Only in a case of unrealistic lossless ENZ films, FIE follows the inverse second power of film thickness predicted by S. Campione, et al. [, vol. 91, no. 12, art. 121408, 2015]. We also predict that FIE could reach values of 100,000 in ultrathin polar semiconductor films. This work is important for establishing the limits of plasmonic field enhancement and the development of near zero refractive index photonics, nonlinear optics, thermal, and quantum optics in the ENZ regime.
利用导电薄膜吸收平均功率的电动力学描述，我们给出了由于近零介电常数（ENZ）极化子模式导致的电场强度增强（FIE）的表达式。我们表明，在超薄ENZ薄膜中，FIE达到一个极限，该极限与ENZ损耗的二次方成反比。这在通过原子层沉积生长的一系列示例性铝掺杂氧化锌纳米层中得到了说明。只有在不切实际的无损ENZ薄膜情况下，FIE才遵循S. Campione等人[《物理评论快报》，第91卷，第12期，文章编号121408，2015年]预测的薄膜厚度的二次方反比关系。我们还预测，在超薄极性半导体薄膜中，FIE可以达到100000的值。这项工作对于确定等离子体场增强的极限以及在ENZ regime中近零折射率光子学、非线性光学、热学和量子光学的发展具有重要意义。
