Flat mirror

glass

Aluminium is available as both coated and uncoated. Unprotected aluminium provides greater than 86% reflectance from near UV to mid IR. Aluminium will slowly oxidize, resulting in a loss of reflectance in the UV, and cause slight scattering throughout the spectrum. Unprotected aluminium makes it harder to clean. Enhanced Aluminium is coated with dielectric layers which increase its reflection in certain regions of the spectrum and greatly improves durability. The coating is sensitive to wavelength, angle of incidence and polarisation. Reflectance values can be optimised further by adding more layers to the enhancing overcoat. Typical reflection is 95% average over the wavelength region 450-650 Nm. It is recommended that aluminium has a protective dielectric overcoat as this will also improve abrasion resistance, enabling the product to be handled and cleaned and less susceptible to damage. Contact our multilingual technical sales team and discover how Knight Opticals high quality optical components and superior service can improve your instrumentation and supply chain experience.