This invention is a class of micromirrors with high reflectivity dielectric layer coated on top of micromirror that can be tuned to allow transparency or reflectivity of UV or Visible light to meet the needs of the application. Also disclosed is a top-down fabrication process for the assembly of coated micromirrors using polymer structural material. Includes additional features & methods for: phase shift mask, sharp turn off, flexible micromirror arrays, and thermal compensation.