Ensuring the Flatness of Mirrors

For high power laser applications - mirrors are typically produced by treating a flat substrate with several layers of ultra hard dielectric coating. Unfortunately these hard dielectric coatings cause a surface which is perfectly flat before coating to pull after coating and to induce that surface to become more convex. Whilst each type of coating behaves uniquely depending on coating design, type of material, aspect ratio of the blank and internal stresses, Optical Surfaces has developed expertise to mitigate the uncertainties associated with the coating to ensure flatness, and hence the performance of the mirror.

Benefiting from a unique thermally stable manufacturing environment, and working with high-stability materials such as fused Quartz and Zerodur, Optical Surfaces is able to routinely achieve a surface accuracy of better than lambda/10 p.v. and surface roughness of less than 1nm on flats and mirrors (coated flats) up to 600mm in diameter. In addition to circular flats and mirrors (coated flats), Optical Surfaces is experienced in producing flats and mirrors in other shapes, light-weighted mirrors and supplying high precision mounts.