The 10Z20DM.11 Laser Line Dielectric mirror is a highly efficient reflector optimized for the 532 nm wavelength. This 1 inch (25.4 mm) diameter mirror is made from a 6.0 mm thick Zerodur substrate. Zerodur is a glass-ceramic material where thermal expansion is nominally zero. This extra stability can be critical for applications requiring diffraction limited performance. The DM.11 coating is designed for use with low-power Nd:YAG lasers and has a center wavelength of 532 nm. The coating achieves greater than 99% reflectance, from 0–45° angle of incidence, for any polarization. This multilayer dielectric coating is extremely durable, making it resistant to damage from repeated cleaning. This mirror has a λ/10 surface flatness and a 15-5 surface quality.