Department of Materials Science and Engineering

Raman spectroscopy is similar to infrared spectroscopy in that it helps the researcher determine the vibrational, rotational and other low-frequency modes of a sample. A laser beam in the visible, rear infrared, or near ultraviolet range is scattered by the sample and reacts with the phonons which results in shifting the laser photons. The energy shift is detected and output as a spectra which can be interpreted to determine the different modes in the sample.  

The GOM group at Iowa State University has two different Raman Spectrometers. The first is a Bruker FT-Raman Spectrometer and the second is a Renishaw Dispersive Raman Spectrometer. The difference between the two lies in that the Dispersive Raman uses a diffraction grating spectrometer to disperse the light scattered by the sample. The light is then detected by a multi-channel detector and the wavelengths of light are the detected Raman Spectra. The FT-Raman uses an iterferrometer creates a path difference between the source and signal beams to create an interferrence pattern. From that interferogram the Raman spectra is reconstructed.