Selection of Mirror Coating
Coating Type	Reflection Band	Feature	Applicable Scene
Al Coating	UV-VIS-NIR(200–2000 nm)	Broad spectrum and highly reflective, easy to oxidize and need protection	Lasers, microscopes, imaging systems
Ag Coating	VIS-NIR(400–20000 nm)	Highest visible & near infrared reflectivity (>95%), but easily vulcanized	High power laser, spectrometer
Au Coating	NIR-FIR(700 nm–20+ μm)	Very high IR reflectivity (>98%), chemically stable	CO₂ laser, infrared sensing
Dielectric Coating	Specific wavelengths (e.g. 532 nm, 1064 nm)	Laser high reflectance (HR) coating, low absorption	Laser resonant cavities, precision optics

On which side is a right angle prism normally coated with a reflective coating?
Hypotenuse coating: most common, light enters at a right angle edge, is fully reflected by the hypotenuse and exits at another right angle edge.
Right angle edge coating: specially designed for specific light path transitions.