Many optical glasses are chemically and environmentally sensitive. Lenses fabricated from these glasses can stain over time leading to transmission degradation. The OTR coating was developed after a careful study of coating diffusion and surface chemistry at the optic-coating interface. The OTR coating eliminates optic staining in even the most hot-humid use environments.

In the optics pictured here, are glass windows made from humidity-sensitive glass after storing in a hot-humid environment for 1 month. The window coated with an industry-standard AR (left) is visibly stained and has a lower transmission. The window coated with the Optimax OTR coating resists staining and ensures good transmission even in the most hot-humid use environments.