The 45701 is a 2 inch [50.8 mm] square mirror, 6.35 mm thick and optimized for 200 to 10,000 nm. This crown glass broadband mirror uses an AlMgF₂ coating to enhance UV reflectance. Surface quality is 80-50, flatness is 1λ. Reflectance is 75% or greater from 200 to 400 nm. The 45701 has a 9.5x10-6K^-1 coefficient of expansion, and is not intended for high power or energy density use.