Open AccessWaveguide-enhanced Raman spectroscopy of trace chemical warfare agent simulants
Author(s) -
Nathan F. Tyndall,
Todd H. Stievater,
Dmitry A. Kozak,
K.P. Koo,
R. Andrew McGill,
Marcel W. Pruessner,
William S. Rabinovich,
Scott A. Holmstrom
Publication year - 2018
Publication title -
optics letters/optics index
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.43.004803
Subject(s) - dimethyl methylphosphonate , raman spectroscopy , materials science , sorbent , nanophotonics , analytical chemistry (journal) , optics , optoelectronics , inorganic chemistry , chemistry , organic chemistry , adsorption , physics
We report the measurement of waveguide-enhanced Raman spectra from trace concentrations of four vapor-phase chemical warfare agent simulants: dimethyl methylphosphonate, diethyl methylphosphonate, trimethyl phosphate, and triethyl phosphate. The spectra are obtained using highly evanescent nanophotonic silicon nitride waveguides coated with a naturally reversible hyperbranched carbosilane sorbent polymer and exhibit extrapolated one-σ detection limits as low as 5 ppb. We use a finite-element model to explain the polarization and wavelength properties of the differential spectra. In addition, we assign spectral features to both the analyte and the sorbent, and show evidence of changes to both due to hydrogen bonding.