Stand-off detection of solid targets with diffuse reflection spectroscopy using a high-power mid-infrared supercontinuum source.

We measure the diffuse reflection spectrum of solid samples such as explosives (TNT, RDX, PETN), fertilizers (ammonium nitrate, urea), and paints (automotive and military grade) at a stand-off distance of 5 m using a mid-infrared supercontinuum light source with 3.9 W average output power. The output spectrum extends from 750-4300 nm, and it is generated by nonlinear spectral broadening in a 9 m long fluoride fiber pumped by high peak power pulses from a dual-stage erbium-ytterbium fiber amplifier operating at 1543 nm. The samples are distinguished using unique spectral signatures that are attributed to the molecular vibrations of the constituents. Signal-to-noise ratio (SNR) calculations demonstrate the feasibility of increasing the stand-off distance from 5 to ~150 m, with a corresponding drop in SNR from 28 to 10 dB.

[1]  Herbert O. Moser,et al.  Post-blast detection of traces of explosives by means of Fourier transform infrared spectroscopy , 2009 .

[2]  Chase A. Munson,et al.  Laser-induced breakdown spectroscopy for detection of explosives residues: a review of recent advances, challenges, and future prospects , 2009, Analytical and bioanalytical chemistry.

[3]  B I Vasil'ev,et al.  IR differential-absorption lidars for ecological monitoring of the environment , 2006 .

[4]  Jacob Grun,et al.  Identification of Explosives with Two-Dimensional Ultraviolet Resonance Raman Spectroscopy , 2008, Applied spectroscopy.

[5]  Takenobu Suzuki,et al.  Ultrabroadband supercontinuum generation from ultraviolet to 6.28 μm in a fluoride fiber , 2009 .

[6]  Marco Leona,et al.  Fiber optics reflectance spectroscopy: a unique tool for the investigation of Japanese paintings , 2001 .

[7]  Peter R. Griffiths,et al.  Diffuse reflectance measurements by infrared Fourier transform spectrometry , 1978 .

[8]  A. Pettersson,et al.  Laser-based standoff detection of explosives: a critical review , 2009, Analytical and bioanalytical chemistry.

[9]  J. Stewart.  Infrared Absorption Spectra of Urea, Thiourea, and Some Thiourea‐Alkali Halide Complexes , 1957 .

[10]  R. A. McGill,et al.  Stand-off detection of trace explosives via resonant infrared photothermal imaging , 2008 .

[11]  N. Gallagher,et al.  Multivariate Curve Resolution Applied to Infrared Reflection Measurements of Soil Contaminated with an Organophosphorus Analyte , 2006, Applied spectroscopy.

[12]  A. Savitzky,et al.  Smoothing and Differentiation of Data by Simplified Least Squares Procedures. , 1964 .

[13]  Wim Bakker,et al.  CCSM: Cross correlogram spectral matching , 1997 .

[14]  Marcos Dantus,et al.  Standoff and arms-length detection of chemicals with single-beam coherent anti-Stokes Raman scattering. , 2009, Applied optics.

[15]  A. Klooster,et al.  Power scalable visible supercontinuum generation using amplified nanosecond gain-switched laser diode , 2008, 2008 Conference on Lasers and Electro-Optics and 2008 Conference on Quantum Electronics and Laser Science.

[16]  Roger J. Green,et al.  Remote identification of chemicals concealed behind clothing using near infrared spectroscopy. , 2011, Analytical methods : advancing methods and applications.

[17]  John T. Rayner,et al.  SpeX: A Medium‐Resolution 0.8–5.5 Micron Spectrograph and Imager for the NASA Infrared Telescope Facility , 2003 .

[18]  P. B. Wagh,et al.  Micro structural investigations on TNT and PETN incorporated silica xerogels , 2010 .

[19]  Bernhard Lendl,et al.  Stand-off Raman spectroscopy , 2009 .

[20]  W. Kessler,et al.  Ultrasensitive dual-beam absorption and gain spectroscopy: applications for near-infrared and visible diode laser sensors. , 1995, Applied optics.

[21]  Michael D. Steven,et al.  High resolution derivative spectra in remote sensing , 1990 .

[22]  R. Sausa,et al.  Laser photofragmentation-fragment detection and pyrolysis-laser-induced fluorescence studies on energetic materials. , 1999, Applied optics.

[23]  S. Gunasekaran,et al.  Infrared, optical absorption, and EPR spectroscopic studies on natural gypsum , 2009 .

[24]  Gwenael Mazé,et al.  Mid-infrared supercontinuum generation to 4.5 microm in ZBLAN fluoride fibers by nanosecond diode pumping. , 2006, Optics letters.

[25]  O Chiantore,et al.  Mid-IR fiber-optic reflectance spectroscopy for identifying the finish on wooden furniture , 2011, Analytical and bioanalytical chemistry.

[26]  Richard E. Whipple,et al.  Standoff Detection of High Explosive Materials at 50 Meters in Ambient Light Conditions Using a Small Raman Instrument , 2005, Applied spectroscopy.

[27]  P. Griffiths,et al.  Mid-Infrared Diffuse Reflection of a Strongly Absorbing Analyte on Non-Absorbing and Absorbing Matrices. Part I: Homogeneous Powders , 2008, Applied spectroscopy.

[28]  Robert W. Field,et al.  INFRARED ABSORPTION OF EXPLOSIVE MOLECULE VAPORS , 1997 .