Field enhancement of epsilon-near-zero modes in realistic ultrathin absorbing films

Abstract Using electrodynamical description of the average power absorbed by a conducting film, we present an expression for electric-field intensity enhancement (FIE) due to epsilon-near-zero (ENZ) polariton modes. We show that FIE reaches limit in ultrathin ENZ films inverse second losses. This is illustrated exemplary series aluminum-doped zinc oxide nanolayers grown atomic layer deposition. Only case unrealistic lossless films, follows film thickness predicted S. Campione, et al. [ Phys. Rev. B , vol. 91, no. 12, art. 121408, 2015]. also predict could reach values 100,000 polar semiconductor films. work important establishing limits plasmonic field and development near zero refractive index photonics, nonlinear optics, thermal, quantum optics regime.