We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly, and further numerically demonstrate that the graded metallic films can serve as a novel optical material for producing a broad structure in both the linear and SHG response and an enhancement in the SHG signal.
@article{arxiv.physics/0407130,
title = {Second-harmonic generation in graded metallic films},
author = {J. P. Huang and K. W. Yu},
journal= {arXiv preprint arXiv:physics/0407130},
year = {2009}
}