They are coated with multi-layer all dielectric. Cold mirror reflects more than 90% of visible light(400nm-700nm) while allowing better than 80% transmission of near-infrared light when the angle of incidence is 45 degree. Cold mirrors are useful for illumination systems where high temperature lighting is not desired.
Item
Specifications
Material
N-BK7;schott B270 or others
Dimension X×Y(φ)
1×1mm~25.4×25.4mm；φ3~φ25.4mm
Dimension tolerance
±0.05mm
Parallelism
＜10 seconds
Clear Aperture
85%
Surface Quality
MIL40-20
Flatness(per 10mm)
λ/10@632.8nm
Reflectance
Cold Mirror: AOI 45°,Ravg>90@420-630nm;
Hot Mirror：AOI 0°, Tavg>90@750-1200nm
Transmission
Cold Mirror: AOI 45°,Tavg>85@750-1200nm;
Hot Mirror：AOI 0°, Ravg>85@420-630nm