In order to manufacture fine optical performance surface of aspheric silicon carbide(SiC) mirror

the technology of surface modification for SiC mirror is presented

and the technology of fabrication of surface modification aspheric SiC mirror is studied. First

ways of surface modification on SiC mirrors are introduced

and especially the technology of ion beam assisted deposition(IBAD)-Si on SiC mirror surface is emphasized.Then several polishing agents

such as CeO2

Al2O3 and SiO2

are used in experiments for polishing SiC samples with surfaces modification. It is verified that high polishing efficiency is acquired in experiment with polishing agent of CeO2

and the best optical surface is fabricated in experiment with polishing agent of SiO2. Finally

on the basis of experiments

650mm×200mm off-axis aspheric SiC mirror with surface modification is manufactured by the technology of computer-controlled optical surfacing. The testing results indicate that the surface accuracy of the aspheric SiC mirror with surface modification is better than λ/50(RMS)（λ=0.6328μm）

and surface roughness is less than 1nm(RMS).