For most mirror applications, metallic coatings offer the best performance/cost ratio over any other reflective coating. The three most common and effective types that Esco Optics offers are aluminum, silver, and gold. Please not other specialty coatings are available by request. 

Several dielectric coatings are available as overcoats, used to enhance reflectivity, durability, and/or longevity of the underlying metal. 

Aluminum (AL)

Bare aluminum provides excellent reflectivity from the UV to the IR. Unfortunately, it also oxidizes rapidly and use of a dielectric overcoat is usually required to prevent degradation. Since no overcoat is ideal for all applications, materials best suited to the intended application should be chosen.

Aluminum-Silicon Monoxide (AL SIO)

Benefits:

• General purpose Aluminum coating for use in the visible spectrum
• Inexpensive

Trade-Off:

• Poor UV reflectance

Aluminum-Magnesium Fluoride (AL MGF2)

Benefits:

• General purpose Aluminum coating for use in the UV and visible spectra
• Relatively inexpensive

Trade-Off:

• Very poor durability, special care must be taken when handling or cleaning

Enhanced Aluminum (AL ENH)

Benefits:

• Special Aluminum coating for higher reflectivity in the visible spectrum

Trade-Off:

• Poor out-of-band reflectivity

Silver (AG)

Benefits:

• Excellent reflectivity from the visible to the far infrared
• Durable overcoat allows front surface use without risk of silver oxidation

Trade-Off:

• Cost
• Poor UV reflectivity

Gold (AU)

Benefits:

• Excelled reflectivity from the visible to the far infrared (best 2-12µm)
• Low scatter surfaces

Trade-Off:

• Cost
• Poor UV, visible reflectivity
• Poor durability

Our coatings are custom products, please Contact Us to place an order.