The 3MD10RM.2 Laser Line Dielectric mirror is a highly efficient reflector optimized for the 325 nm wavelength. This 1.181 inch (30.0 mm) diameter mirror is made from a 6.0 mm thick Borofloat® 33 substrate. Borofloat has low thermal expansion and is an excellent substrate for most applications. The RM.2 coating is designed for use with HeCd lasers and has a center wavelength of 325 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/5 surface flatness and a 20-10 surface quality.