metal coating
Bare aluminum coatings are excellent reflectors in the upper UV, visible, and near infrared. The surface is soft and must be handled with care. Enhanced aluminum is a multilayer film of dielectrics on top of aluminum is used to enhance the reflectance in the visible or ultraviolet region. The multilayer film also provides the handling characteristics of the protected aluminum coating. Protected aluminum coating is used as an overcoat to protect the delicate aluminum. This treatment provides an abrasion resistant surface while maintaining the performance of aluminum.
Gold coatings provide consistently high reflectance in the near-IR to far-IR, and are the most widely used material in these regions. Gold however is soft and easily scratched. Protected gold laser mirror coatings are also available. These provide the same performance as gold coatings, with additional abrasion resistance.
Chromium coating has a reflectivity of approximately of 80% throughout the visible spectrum. Chrodium coated nickel is considerably more durable then glass substrates both to thermal and physical damage.
Silver coatings for laser mirrors are superior in reflectance to aluminum, however its strong tendency to oxidize and tarnish means that it must be thoroughly sealed from the atmosphere in order to avoid degradation.
Dielectric overcoats also improve handling of metallic mirrors, increase the durability of the metal coating, provide protection from oxidation, and enhance the reflectance of the metal coating in specific spectral regions. Metal coatings are 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 other than clean, dry air. Isopropyl alcohol or acetone can be used to clean metal mirrors with a dielectric coating.
Diameter | 1-320 mm |
Diameter Tolerance | +0/-0.1 mm |
RMS irregularities (RMSi) | 25 nm |
Surface imperfections (Scratch/Dig) | 20 - 10 |
Coating | Customer specific(Aluminum, Au, Siliver and so on) |
Measurement | Full-surface interferometric |
Material | Customer specific (almost any type of glass, quartz glass, silicon, ZERODUR®) |
Mounting | Customer specific |