RAMAN CONFOCAL MICROPROBING, IMAGING AND FIBEROPTIC REMOTE-SENSING - A FURTHER STEP IN MOLECULAR ANALYSIS

This paper reviews some recent developments in Raman instrumentation. The introduction of the confocal design in most Raman spectrometers represents the latest advance in the field of instruments for Raman spectroscopy. It is the basis of new applications in the field of Raman microprobing and improvements in Raman imaging techniques. The basic principle of confocal microscopy is reviewed and its extension to Raman spectroscopy is discussed in terms of improved depth resolution which results in better background discrimination. A new concept of Raman imaging is also presented which benefits from the confocal system and overcomes most of the limitations of direct imaging techniques. A dual fibre-optic remote analysis scheme is described which has been developed to optimize the collection of the scattered light while minimizing the interference from the optical fibres.