Metallized Gratings Enable Color Effects and Floating Screen Films by First-Order Diffraction
A new concept for generating visual effects with metallized gratings is introduced. Shadow evaporation of aluminum onto dielectric gratings is shown to produce strongly asymmetric color effects. Zero-order effects are combined with +/- first-order transmission in the present structures to generate not only polarization but also orientation-dependent colors. We show that a wide palette of colors can be obtained by simply scaling the parameters of the dielectric base grating. The present approach therefore enables the fabrication of entire asymmetric images in a two-step process. Additionally, a floating screen film is created by placing the grating at an increased distance to the light source. The present structures could find applications as security or decorative elements and are well suited for mass production using high-throughput techniques such as roll-to-roll fabrication.