Raman Spectrometer

    Raman Spectroscopy is a non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphy, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material. Raman is a light scattering technique, whereby a molecule scatters incident light from a high intensity laser light source. Most of the scattered light is at the same wavelength as the laser source and does not provide useful information – this is called Rayleigh Scatter. However a small amount of lightis scattered at different wavelengths, which depend on the chemical structure of the analyte – this is called Raman Scatter. A Raman spectrum features a number of peaks, showing the intensity and wavelength position of the Raman scattered light. Each peak corresponds to a specific molecular bond vibration. In a Raman micro spectrometer the sample is illuminated with a laser beam through an objective of the integrated research grade optical microscope. Light from the focal spot is collected in back reflected mode with the same high quality microscope objective and sent through a spectrograph. Frequencies close to the laser line, due to elastic Rayleigh scattering, are filtered out while the rest of the collected light is dispersed onto a two dimensional detector (spectroscopic quality CCD).