Mirror coatings are designed to achieve the maximum reflectivity over the widest spectrum of wavelengths. There is always a trade off, in that the wider the range of operating wavelengths, the lower the overall reflectance.
Protected Silver has a similar performance to Gold coating in the near infra red, but the visible performance is better for silver. Gold coatings can be used at Terahertz frequencies. Protected Silver is more durable.
Enhanced coatings for specific wavelengths such as 633nm, see below, or 10.6 microns wavelength such as our MaxR coating.
Specify angle of incidence, wavelength(s) and polarization
Very thin mirrors may distort due to tensile and compressive forces in the thin film coating layers
A small perimeter area will be uncoated
High reflectivity e.g 99.8%+ can only be achieved over a small spectrum
Thin Film modeling software can allow a coating to be designed and characterized.