Ion beam assisted smoothing of optical surfaces

In this work different ion-beam techniques demonstrate their capability for surface-roughness reduction down to the sub-nanometer scale. In ion beam direct smoothing, favorable characteristics in the development of surface topography are exploited and smoothing with the help of planarization layers is evaluated. Focusing on the common optical substrate materials quartz (fused silica) and silicon, it is shown that a surface-roughness reduction down to the {/content/NABDDNNED2NDMAE8/xxlarge8764.gif}0.1 nm root mean square level can be achieved by optimization and combination of these techniques.