Low-Cost Raman Spectroscopy using a Violet Diode Laser

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 11 Issue 2 (2006) pp 88-92

Low-Cost Raman Spectroscopy using a Violet Diode Laser

Patrick Bisson,^† George Parodi,^‡ Diane Rigos,^§ James E. Whitten^†,*

^†Department of Chemistry, University of Massachusetts Lowell, Lowell MA 01854; ^‡Dept. of Chemistry, Saint Anselm College, Manchester, NH 03102; and ^§Dept. of Chemistry, and Merrimack College, North Andover, MA 01845, james_whitten@uml.edu
Received August 17 2005. Accepted December 16, 2005.

Published online: 9 February 2006

Abstract. New generations of diode lasers that emit violet light make possible the assembly of a low-cost Raman spectrometer for use in the student laboratory. Because Raman scattering intensity is inversely proportional to the fourth power of the wavelength of the incident radiation, the use of these violet lasers has advantages over their longer-wavelength counterparts. The higher scattering efficiencies permit the use of a relatively inexpensive PC-based spectrometer (e.g., an Ocean Optics spectrometer) for wavelength analysis of the scattered radiation. Combined with a notch filter and several lenses, the violet diode laser and spectrometer permit the construction of an instrument at a total cost of around $6500, including the PC-based spectrometer. This cost will decrease dramatically in the near future as violet diode lasers are commercialized for data storage applications. Performance of the instrument is demonstrated on carbon tetrachloride, water, and benzene. These experiments show Stokes radiation bands in agreement with published data. While the use of the notch filter and limited resolution of the spectrometer obscure some bands, the instrument serves to illustrate fundamental principles of Raman spectroscopy appropriate for physical and analytical chemistry teaching laboratories.

Key Words: Laboratories and Demonstrations; physical chemistry; analytical chemistry; spectroscopy

(*) Corresponding author. (E-mail: james_whitten@uml.edu)

Article in PDF format (328 KB) HTML format

Supporting Materials: