Circular Variable Neutral Density (CVND) filters are used in high quality optical systems to change the intensity of light from 100 percent to less than 0.1 percent. In a system that uses this technology, the beam intensity changes as the filter rotates due to the density variation of a gradient metallic coating around the filter. […]
Thin-Film Coatings and Their Applications
While the majority of the material in a lens, filter, or mirror is a substrate such as glass, it is the first few nanometers of material that light penetrates that can determine much of the light’s behavior. The application of specialist thin-film coatings has become a major industry and is very important for many applications. […]