Samples and Sample Holders for Raman Spectroscopy

The sample must be placed at the focal point of an intense laser beam, and some samples may be subject to thermal decomposition or photodecomposition. Accessories that spin the sample tube or cup are available, to distribute the laser beam over the sample and reduce heating of the sample. Spinning or rotating the sample minimizes thermal decomposition, but does not stop photodecomposition. Sample spinning is required for resonance Raman spectroscopy, discussed later. 

Raman spectroscopy does not suffer interference from atmospheric water vapor or carbon dioxide, as does IR. Gases do not scatter well, so even though Raman-active bands occur for these gases, the contribution to the Raman signal from air in the optical path is insignificant. Materials in the optical path outside of the laser focus also have negligible scattering. 

Sample cells have been designed for low- and high-tanperature operation, well-plate accessories allow high-throughput analyses, and ronote probes and user-friendly video stages are available for many systems. 

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