title: Standoff Laser-Induced Breakdown Spectroscopy (LIBS) Using a Miniature Wide Field of View Spatial Heterodyne Spectrometer with Sub-Microsteradian Collection Optics.
abstract: A spatial heterodyne spectrometer (SHS) is described for standoff laser-induced breakdown spectroscopy (LIBS) measurements. The spatial heterodyne LIBS spectrometer (SHLS) is a diffraction grating based interferometer with no moving parts that offers a very large field of view, high light throughput, and high spectral resolution in a small package. The field of view of the SHLS spectrometer is shown to be ∼1° in standoff LIBS measurements. In the SHLS system described here, the collection aperture was defined by the 10 mm diffraction gratings in the SHS and standoff LIBS measurements were made up to 20 m with no additional collection optics, corresponding to a collection solid angle of 0.2 μsr, or f/2000, and also using a small telescope to increase the collection efficiency. The use of a microphone was demonstrated to rapidly optimize laser focus for 20 m standoff LIBS measurements.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Barnett
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA.
authors.forename: Nirmal
authors.initials: N
authors.lastname: Lamsal
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA.
authors.forename: S Michael
authors.initials: SM
authors.lastname: Angel
keywords: Laser-induced breakdown spectroscopy; remote LIBS; remote spectroscopy; spatial heterodyne spectrometer; standoff LIBS