Abstract
Ultra precision finishing of conformal, free form, steeply concave or millimeter-size optics is challenging, particularly with sub-aperture processes required to ensure the necessary determinism. Newly developed technology based on the impingement of a jet on a work-piece surface is, on the other hand, well suited for finishing these classes of optics. This will be demonstrated through a series of examples spanning a wide range of materials, geometries and specifications including steeply concave shapes such as domes, and millimeter-sized optics. In particular, a 23mm diameter steep concave lens with a 20mm radius of curvature was polished from λ/10 to better than λ/100 RMS in two iterations. The same precision was achieved on a concave optic with only a 2mm diameter and < 5mm radius of curvature. Roughness better than 1nm RMS is routinely achieved.
