This paper describes a quest to find simple technique to superpolish Zerodur asphere (55µm departure from best fit sphere) that could be employed on old fashion way 1-excenter optical polishing machine. The work focuses on selection of polishing technology, study of different polishing slurries and optimization of polishing setup. It is demonstrated that either by use of fine colloidal CeO 2 slurry or by use of bowl-feed polishing setup with CeO 2 charged pitch we could reach 0.4nm RMS roughness while removing <30nm of surface layer. This technique, although not optimized, was successfully used to improve surface roughness on already prepolished Zerodur aspheres without necessity to involve sophisticated super-polishing technology and highly trained manpower.

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