Metal reflective coatings have an advantage of covering wide band and does not depend very much on polarization the angle of incidence of light but have disadvantage that very delicate to handle and chance of getting scratches easily. Dielectric layers will be coated over the metal to protect the surface as well as some times to enhance the reflection in particular spectral region. Applications of mirror coating includes Lighting Systems, Laser Systems, Illumination Systems, Digital Imaging, Telescope Mirrors, Bar Scanners, IR Imaging Systems and Surveillance   

Protective Aluminium coating

Wavelength Region (nm) Reflection (%) Durability
400 - 700
> 85%
Mil-C-675c, Moderate Abrasion Resistance

Enhanced Aluminium Coating

Wavelength Region (nm) Reflection (%) Durability
450 - 650
> 95%
Mil-C-675c , Moderate abrasion resistance

Protective Silver Coating

Wavelength Region (nm) Reflection (%) Durability
450 - 2000
> 98%
Mil-C-675c, Moderate abrasion resistance

Protective Gold Coating

Wavelength Region (nm) Reflection (%) Durability
700 - 2000
> 97%
Mil-C-675c, Moderate abrasion resistance