Nonpolarizing color mirrors on a high-reflecting metal base

Optically variable devices made from optical-interference coatings create chromatic color mirrors that have minimal polarization differences with increasing incidence angle. These metal-dielectric-metal designs produce narrowband, high reflectance in the visible wavelength region. Broader-band reflectance regions, similar to those created by multilayer dielectric stacks, can be replicated on a high-reflecting metal base such as aluminum, maintaining the same nonpolarizing effects of the narrowband designs. These designs are intended for reflective systems used for display where reduced angle sensitivity is paramount. However, these designs can also be adapted for large angular-dependent color shift, such as in effect pigments. Design examples and layer material suggestions are given depending on the application requirements. (C) 2014 Optical Society of America