New method of obtaining a supersmooth surface with angstrom dimension on optical material

This paper combines nonabrasive polishing with cryogenic polishing and proposes a new method to get super-smooth surface with angstrom dimension -- cryogenic polishing without abrasive. We describe its process and give some experiments to show how to keep stabilization in polishing and how to reduce effects of water quality of ice disk on surface roughness. Experiment results show that modifying ice disk before polishing for eliminating vibration and water quality of ice disk have a vital effect on surface roughness. Experiments of polishing K9(Chinese type) glass with ice disk of tape water, pure water and de-ionized water show that workpiece surface roughness polished by ice disk of de-ionized water is the lowest, up to about Ra 0.5 nanometer (nm). This is a new process to gain super-smooth surface with angstrom level on optical material.