What is an Enhanced or Protected Metal Coating?

Metal coatings are typically very delicate without a protective coating and require extra care during handling and cleaning. The surface of an unprotected metal coating should never be touched or cleaned with anything but clean, dry air.

A dielectric overcoat on a metallic mirror allows for improved handling of the component, increases the durability of the metal coating and provides protection from oxidation with little impact to the performance of the metal coating.

The dielectric layer(s) can also be designed to enhance the reflectance of the metal coating in specific spectral regions. Isopropyl alcohol or acetone can be used to clean our protected metal coated mirrors. 

Protected Aluminum

Standard protected aluminum is our most popular mirror coating for applications in the visible and near infrared. A λ/2 coating of Silicon Monoxide (SiO) is typically used as an overcoat to protect the delicate aluminum. This treatment provides an abrasion-resistant surface while maintaining the performance of aluminum mirror.

Protected aluminum

Enhanced Aluminum

In an Enhanced Aluminum coating, a multi-layer film of dielectrics on top of aluminum is used to increase the reflectance in the visible or ultraviolet regions. This coating is ideal for applications requiring increased reflectance from 400 – 650nm while the UV and DUV Enhanced Aluminum coatings yield increased reflectance from 120 – 400nm range. The multi-layer film also provides the improved handling characteristics of the protected aluminum coating.

Enhanced aluminum