CONFOCAL MICROSCOPY

Confocal microscopy permits non-destructive three dimensional microsco pic imaging of thick translucent specimens or opaque surfaces. The abi lity to generate three dimensional (3-D) images offers unique advantag es in the study of materials. In many cases non-destructive 3-D imagin g is difficult or impossible to perform by conventional light microsco py or other techniques. Confocal microscopy is therefore being increas ingly used in many areas of materials science. This article discusses the principles of confocal microscopy, giving examples of types of con focal microscopes, their commercial availability, and methods of confo cal 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 s urfaces; lithographic processes; semiconductor materials and integrate d circuits; surfactant monolayers: dielectric films; fibre-reinforced composites; power cable insulation; minerals and soils; and optical fi bres. These are given as examples of current applications although the re are probably many more potential future applications of confocal mi croscopy in materials science.