Two methods are described of preparing and investigating cross-section
s of single layer and multilayer optical coatings by atomic force micr
oscopy (AFM). The first consists of mechanical grinding and polishing
followed by a final ion-polishing and etching procedure. The second is
simply mechanically fracturing. The results obtained from both prepar
ation methods are compared. In addition, cross-sectional transmission
electron microscopy has been used to verify the AFM results.