IR coatings at here mean coatings for infrared region in 2.5μm(2500nm)-16μm. There is a big difference in selection of materials and fabrication techniques between IR coatings and near infrared coatings. They are mainly used in industrial and medical laser equipments such as CO2 laser, Er:YAG laser, CO and HF lasers.
High energy CO2 laser coatings (10.6μm) |
Er:YAG Coatings (2.94μm) |
Infrared Imaging system |
>ZnSe/GaAs lens AR R<0.2% note: Ge use low energy laser>ZnSe/GaAs Windows PR/HT 20%-98%/T>99% note: Ge use low energy laser >Si/Cu substrate total Reflectors |
>CaF2/Sapphire Crystal lens AR/AR R<0.2%>CaF2/Sapphire Crystal Windows PR/AR 20%-98%/R<0.2% >BK7/CaF2/Sapphire Substrate mirror |
>Silicon Lens:AR/AR T>98% 3.5-5μm T>60% 7.5-11.5μm note: Oxide Free Si has high absorbtion in 7.5-11.5μm, but the materials is very cheap, so it can use Infrared Imaging System instead of Ge/ZnS/ZnSe materials.>MgF2 Windows AR/AR 3.5-4.8μm T>95% >ZnSe/ZnS/Ge Substrate Lens:AR/AR |