A new high‐resolution dual‐probe system for detecting and imaging thermal and plasma waves

Thermal and plasma waves have been simultaneously and independently probed by a novel differential system. This new detection system for characterising and imaging materials such as semiconductors in a noncontacting, nondestructive manner, is based on two parallel, heterodyne interferometers, which probe the specimen on a microscopic scale. These detect changes in sample reflectivity and surface displacement which are induced by a separate laser source. The optical and electronic configuration is described and results showing the measurement and imaging capabilities of the system are presented. New results indicating interference between photodisplacement and photoreflectance effects are discussed.