A Hard Gold Optical Coating

Abstract

This paper will trace the development of a hard gold electro-deposited coating that was originally developed to solve an engineering problem for Xerox. The plating bath variables that were considered and those that were eventually decided upon will be treated. Test procedures and results for both hardness and reflectance will be illustrated. Applications of this gold coating for mirrors, reflectors, integrating spheres, and diffraction gratings will be discussed. Design considerations, such as its ability to be deposited over glass as well as metal substrates and its diamond machine ability, will be touched upon.