CONFOCAL MICROSCOPY

Confocal microscopy permits non-destructive three dimensional microscopic imaging of thick translucent specimens or opaque surfaces. The ability to generate three dimensional (3-D) images offers unique advantages in the study of materials. In many cases non-destructive 3-D imaging is difficult or impossible to perform by conventional light microscopy or other techniques. Confocal microscopy is therefore being increasingly used in many areas of materials science. This article discusses the principles of confocal microscopy, giving examples of types of confocal microscopes, their commercial availability, and methods of confocal imaging. It then goes on to discuss some applications of confocal microscopy in materials science. Such applications include monitoring and/or analysis of the following: wear (e.g. in machinery); fracture surfaces; lithographic processes; semiconductor materials and integrated circuits; surfactant monolayers: dielectric films; fibre-reinforced composites; power cable insulation; minerals and soils; and optical fibres. These are given as examples of current applications although there are probably many more potential future applications of confocal microscopy in materials science.