Upgrading of the Vibrational Spectroscopy Laboratory at Virginia Tech

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

EAR-0322119 Bodnar During the past decade significant advances have been made in instrumentation for measuring the vibrational spectra of solids, liquids and gases. Modern Raman microprobes use a wavelength-specific polymer notch filter to remove incident radiation and stray light. Earlier designs accomplished this through use of a series of mirrors and lenses that focused the Raman signal onto the detector, with considerable loss of energy along the beam path. As a result, modern Raman instruments have much higher energy throughput and concomitantly, significantly lower detection limits for all covalently bonded species. This project will upgrade the capabilities of the Vibrational Spectroscopy Laboratory at Virginia Tech by acquiring a Raman microprobe that employs a visible wavelength laser (514 nm), as well as a state of the art system that uses an ultraviolet laser (325 nm) as the excitation source. Unlike the visible system, this latter system is not affected by fluorescence from the sample, permitting analysis of organic compounds and other phases that fluoresce when illuminated. The instruments will be applied in a variety of new and ongoing projects, including development of techniques for determining water contents of silicate melt inclusions, quantitative analysis of carbon dioxide and methane-bearing fluid inclusions, analysis of petroleum fluid inclusions and in situ characterization of corrosion products in natural and anthropogenic environments.