Metal Optics Replace Metal Coated Substrates

The primary function of an optical mirror is to redirect light. The mirror should be flat, smooth, and provide a durable, stable and easy-to-clean surface. For many applications, a mirror's ability to conduct heat is also extremely important. Common metallic optics mirrors have an Aluminum or Gold coating on various substrate materials of glass, Fused Silica or Fused Quartz. Left unprotected, Aluminum and Gold mirror coatings are extremely delicate and cannot withstand much cleaning. These mirrors must then be overcoated with dielectric materials which are much harder than the metal surface they are protecting. These coatings also have inconsistent thickness variation, and may distort the wavefront of the deflected beam. Also, differences in the coefficient of expansion between the substrate and coating materials affect the mirrors' stability.