Teflon laps: some new developments and results

The process of superpolishing with Teflon laps has enabled supersmooth [< 0.1 nm rms] and extremely flat (λ/100) optical surfaces to be produced on a large range of amorphous and crystalline optical materials. Stable surface conditions and the very low wear of a Teflon lap during polishing provide an opportunity to examine the effects of varying different polishing parameters. These include sample-tolap mismatch and the influence of different polishing compounds and fluid chemistry. The results show that when large optical flats are superpolished with Teflon laps, microroughness, subsurface damage, and scattering can be minimized and reliably and consistently predicted for a wide variety of optical materials, while extremely flat surfaces are simultaneously achieved.