Vacuum coating
For the deposition of high-purity metal or dielectric materials on surfaces, all disturbing influences must be eliminated. Therefore, these coatings are produced under high vacuum conditions. At a very low ambient pressure, which is less than 10-3 mbar, i.e. just less than 1 millionth of the normal ambient pressure. Under these conditions, fewer disruptive influences occur.
Further information on vaccum coatings and different technologies for optical coatings
