In order to obtain high quality supersmooth surface of zerodur

a sophisticated supersoomth surface polishing method—stable eccentric immersed polishing was adopted. Firstly

the property and microstructure of zerodur were analysed

and the technical condition for supersoomth surface polishing was proposed. Secondly

the principle and technical process of the polishing method were discussed. By this polishing technology

the sub-nano scale supersmooth surface of zerodur was successfully and stably obtained. Roughness reached to Ra0.3nm. Lastly

through the transform from roughness curve to Hilbert spectrum

the effects between polishing technological parameters and surface roughness were found. The results show that

the adoption of HHT for the measurement and evaluation of supersmooth surface can provide effective instruction to the practical polishing process

and redounds to obtain high quality supersmooth surface.