Human color vision provides nanoscale accuracy in thin-film thickness characterization

We study how accurately a naked human eye can determine the thickness of thin films from the observed color. Our approach is based on a color-matching experiment between thin-film samples and a simulated color field shown on an LCD monitor. We found that the human color observation provides an extremely accurate evaluation of the film thickness, and is comparable to sophisticated instrumental methods. The remaining color differences for the matched color pairs are close to the literature value for the smallest visually perceivable color difference. (C) 2015 Optical Society of America