Our chemically deposited Gold mirror coating is perfect for the mid and deep infra red, but in response to customer demand we also offer mirrors with Protected Silver, and Protected Aluminium coatings.
Protected Silver is better for applications in the visible and near infrared, as Silver loses reflectivity towards the UV. We are very pleased with this coating, it is durable to cleaning, withstands high temperatures, and has a long shelf life.
So far we have applied it to Aluminium mirror substrates, and to Copper mirrors. It is aimed at applications in the visible and near infrared up to about 5um wavelength. For wavelengths longer than this then Gold is the better choice. It is very similar to the protected silver coating offered by catalogue companies on BK7 or Fused Silica glass mirrors, but with metal mirrors, tapped holes, dowels, flanges and bezels can be incorporated in the mirror itself. Looking through several of the optical catalogues, the mirror mounts can cost more than the mirrors. A custom metal mirror with a protected silver coating, can be far cheaper than a glass mirror with protected silver coating plus the extra mirror mount….
Click the thumbnail to see a scan from a recent mirror coating run applied to lightweight Aluminium fold mirror