Remote Chemical Detection with Tunable Lasers: Applications in Threat Detection and Forensics

1. SPSA / SIPR Conference 2010 Remote Chemical Detection by Tunable Lasers : Potential applications in Threat Detection and Forensics Dr Graeme Malcolm

2. Acknowledgements • Co-authors: • G.T. Maker, B.Miller & G. Robertson,M Squared Lasers Ltd • M.H. Dunn and D.J.M Stothard,University of St. Andrews, UK • Co-workers : • C.R Howle, A McIntosh, L.Lee and C.Dyer • Defence Science and Technology Laboratory (DSTL), Porton Down, UK • Work supported by: • DSTL, MoD, Royal Society of Edinburgh, Scottish Enterprise.

3. Overview • Active IR hyperspectral sensing concept • Source requirements • Source & imaging system • Results • Threat Detection and Forensic Applications • Conclusion and Summary

4. Introduction • Problem: real-time detection & imaging of threat materials at safe distances • CWAs, BWAs, IEDs, TICs • Ideally detect many agents with one device • ‘Safe’ distance typically ten(s) metres www.m2lasers.com

5. Stand-off Concept Threat Detection Concept • M Squared Current Capability • CWA Sensing Confidential - Feb ‘09

6. C O C N C N C C Typical absorption wavelengths of molecular bonds in common organic molecules C C X-H attached tohetero-atoms C-H Doubles Triples Singles N H O H 4000 2300 1500 cm-1 2800 1800 3200 2100 4000 3000 2000 1000 cm-1 2.5 3.3 5.0 10 µm Application Requirements:IR Threat Signatures www.m2lasers.com

7. Active IRHyperspectral Remote Sensing- Concept • Use strong absorptions of target molecules or compounds in the IR waveband • Illuminate scene with IR light of high spectral purity to coincide with absorption features • Collect back-scattered light • Target molecule/compound in path of beam will absorb and reduce backscatter • Negative Contrast Imaging • Tunable IR source • Different absorption features measured and spectroscopic identification possible

8. Spectroscopic survey of line strengths of in the 3-5µm infrared region CO2 10 -17 OCS N2O HCN HCI PH3 10 -18 CO C2H2 CH4 H2CO HBr GeH4 10 -19 C2H6 OH C2N2 Line Strength (cm/molecule) NH3 C2H4 10 -20 NO2 CH3CI O3 HI H2O SO2 10 -21 H2S BTEX 10 -22 3.0 3.5 4.0 4.5 5.0 Wavelength (µm)

9. Source Requirements • Sensitivity & specificity require sources with: • High power & brightness (for range, high SNR) • Broad wavelength tuning (cover many species) • Suitable linewidth (selectivity) • High efficiency and compactness (portability) • Lack of suitable IR illuminators has hindered adoption of active IR hyperspectral sensing

10. Novel IR Illuminator - Firefly-IR • OPO = broad tuning, dual NIR & MWIR outputs • Intracavity OPO = high efficiency • Integrated pump = compact • Designed for field use: • Maintenance-free design • Instrument Control by Ethernet • InvarianT™alignment-free mounts 36 x 21 x 7cm (L x W X H)

11. Pump Typical Tuning Curve - MWIR Output, Broadband Signal Idler PPLN (Optional étalons) QS Nd:YV04 pump M2 < 1.4 at 3.3µm Firefly-IR:Performance Characteristics • Tuning ranges: • 1.4 - 1.8 µm (>300 mW) • 2.8 - 4.6 µm (>120 mW) • Pulse repetition rate: • Up to 300 kHz • Pulse width: • < 10 ns (FWHM) • Linewidth: • < 6 cm-1 (no étalons) • < 2 cm-1 (signal étalon)

12. Galvanometermirror From Firefly-IR CaF2 Lens MCT Detector Firefly-IR + Scanner:Imaging Raster : Backscatter Absorption Gas Imaging for Gases Active Reflectance / Absorption Imaging of Liquids/Solids

13. Video-Rate Imaging of Gases Normal video:gas is invisible What Firefly saw – methane gas

14. Firefly-IR + Scanner:Imaging Applications Demonstration of gas imaging and false colour concentration measurement with Firefly-IR using differential absorption

15. Firefly-IR + Scanner:Concentration Resolution & range • Sensitive CH4 monitoring • Detection to <35 ppm.m • Real-time imaging

16. Identification of Liquids • Spectral fingerprinting of liquids : various mineral oils

17. Spectroscopic & spatial negative contrast imaging of mineral oils – with differential analysis Identification of Liquids II Z ~1.2 m

18. Imaging Threat Simulants: Forensics : Attempted to remove CWA simulant but still detectable Z ~1.2 m www.m2lasers.com

19. Applications in Threat Detection / Forensics • Identifying threats • Security & venue protection • Counter Terrorism screening • Decontamination • Identifying effective decontamination requirements • Triage • Understanding nature of attack substance • Forensic Investigation • Ability to investigate a scene remotely and chemically map evidence.

20. THz Imaging for Drug Detection • The Importance of Terahertz: • New spectroscopic area important for molecular identification • Like X-rays but non-ionising – not dangerous • Drug detection and Identification • Leveraging pharmaceuticals non-destructive testing / analysis THz Spectral Fingerprinting Ecstasy Aspirin Meth

21. Summary • Demonstrated active IR spatial/spectral detection of gases and liquids • Gases down to 10ppm.m at >10m • Liquids down to 20ul at 10m • Solids down to ng of residue • Novel laser sources provides newcapabilities for threat agent imaging with potential applications in: • Detection of CWAs and Explosive Materials • Counter-terrorism and forensic investigation • Drug detection and analysis

22. graeme@m2lasers.com