Elliptical Mirror, Silver, Borofloat, 46.7 x 66 mm, λ/10, 480-20,000 nm

The 18E20ER.2 Broadband Silver Elliptical Mirror is an excellent general purpose, broadband reflector. This 46.70 mm (1.838 inch) minor axis, 66.04 mm (2.60 inch) major axis, elliptical mirror is made from a 12.45 mm thick Borofloat® 33 substrate. Borofloat® 33 has low thermal expansion and is an excellent substrate for most applications. Our ER.2 protected silver coating is composed of a low emissivity silver film fully encapsulated by a multilayer dielectric stack to prevent oxidation. This coating has excellent broadband reflectivity in the IR, while maintaining very good performance in the visible and near IR. The 18E20ER.2 has an average reflectivity greater than 96% from 480-1100 nm and greater than 98.5% from 1.1-20 µm. This mirror has a λ/10 surface flatness and a 15-5 surface quality.