A novel process for polishing lenses made of fused silica and BK7 with CO2-laser radiation is presented. Due to the increasing demand in the optics industry for aspherical or freeform lenses in optical systems, new manufacturing processes are required. With this polishing technique, the roughness on plane fused silica surfaces can be reduced to Rq<4 nm (1 × 1 mm2) and Wq<10 nm (20 × 20 mm2) [1–3]. First results on polishing spherical and aspherical lenses of fused silica and BK7 with an adapted processing strategy are presented. The roughness achieved on those samples is similar to the results on plane samples with a form deviation of less than 1 µm for the whole lens. To polish non-plane optics, homogeneously adapting of the energy deposition to the surface geometry is required. The processing rates for all geometries are, at up to 1 cm2/s, several times faster than conventional polishing techniques, especially for geometries like aspheres or freeform optics.
© 2012 Optical Society of AmericaPDF Article