Ultraviolet Stand-off Raman Measurements Using a Gated Spatial Heterodyne Raman Spectrometer

Nirmal Lamsal; Shiv K Sharma; Tayro E Acosta; S Michael Angel

doi:10.1177/0003702816631304

Ultraviolet Stand-off Raman Measurements Using a Gated Spatial Heterodyne Raman Spectrometer

Appl Spectrosc. 2016 Apr;70(4):666-75. doi: 10.1177/0003702816631304. Epub 2016 Feb 16.

Authors

Nirmal Lamsal¹, Shiv K Sharma², Tayro E Acosta², S Michael Angel³

Affiliations

¹ Department of Chemistry and Biochemistry, The University of South Carolina, Columbia, South Carolina, USA.
² Hawaii Institute of Geophysics & Planetology, University of Hawaii, Honolulu, Hawaii, USA.
³ Department of Chemistry and Biochemistry, The University of South Carolina, Columbia, South Carolina, USA smangel0@mailbox.sc.edu.

PMID: 26883731
DOI: 10.1177/0003702816631304

Abstract

A spatial heterodyne Raman spectrometer (SHRS) is evaluated for stand-off Raman measurements in ambient light conditions using both ultraviolet (UV) and visible pulsed lasers with a gated ICCD detector. The wide acceptance angle of the SHRS simplifies optical coupling of the spectrometer to the telescope and does not require precise laser focusing or positioning of the laser on the sample. If the laser beam wanders or loses focus on the sample, as long as it is in the field of view of the SHRS, the Raman signal will still be collected. The SHRS is not overly susceptible to vibrations, and a vibration isolated optical table was not necessary for these measurements. The system performance was assessed by measuring stand-off UV and visible Raman spectra of a wide variety of materials at distances up to 18 m, using 266 nm and 532 nm pulsed lasers, with 12.4 in. and 3.8 in. aperture telescopes, respectively.

Keywords: FT Raman; Interferometry; Raman spectroscopy; Remote Raman; Spatial heterodyne Raman spectrometer (SHRS); Stand-off Raman; Ultraviolet (UV) Raman.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.