2009 Advanced Laboratories Conference Abstract Detail Page

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Abstract Title: Raman Spectroscopy
Abstract: When light is scattered from a molecule or crystal, most photons are elastically scattered. The scattered photons have the same energy (frequency) and, therefore, wavelength, as the incident photons. However, a small fraction of light (approximately 1 in 107 photons) is scattered at optical frequencies different from, and usually lower than, the frequency of the incident photons. The process leading to this inelastic scatter is termed the Raman effect. Raman scattering can occur with a change in vibrational, rotational or electronic energy of a molecule. If the scattering is elastic, the process is called Rayleigh scattering. If it's not elastic, the process is called Raman scattering. Raman scattering (or the Raman effect) was discovered in 1928 by V. C. Raman who won the Nobel Prize for his work. If the substance being studied is illuminated by monochromatic light, for example from a laser, the spectrum of the scattered light consists of a strong line (the exciting line) of the same frequency as the incident illumination together with weaker lines on either side shifted from the strong line by frequencies ranging from a few to about 3500 cm-1. The lines of frequency less than the exciting lines are called Stokes lines, the others anti-Stokes lines. Raman spectroscopy is very important practical tool for quickly identifying molecules and minerals. A Raman spectrometer was deployed on the Viking landers in 1972 and in other missions. Raman spectroscopy also has important scientific applications in studying molecular structure. In this experiment we will study both kinds of applications. A set of real, man-made, and optically equivalent diamonds will be provided as a final project.
Abstract Type: Workshop
Session: Session V - Parallel Workshops

Author/Organizer Information

Primary Contact: Faculty or Staff
University of Michigan