Dr. Robert James Stokes Profile

Dr. Robert James Stokes

Business Manager at Agilent Technologies

SPIE Involvement:

Editor | Author

Proceedings Article | 17 October 2023 Presentation + Paper

Explosive and precursor identification using a portable spatially offset Raman spectroscopy (SORS) device

Robert Stokes, Brian Foulger, Ana Blanco-Rodriguez, Pik Leung Tang, Kate Whitaker, Thierry Pope

Proceedings Volume 12742, 1274209 (2023) https://doi.org/10.1117/12.2684355

KEYWORDS: Raman spectroscopy, Explosives, Safety, Spectrometers, Improvised explosive devices, Laser safety, Decision making, Beryllium

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Proceedings Article | 20 September 2021 Paper

Detection and identification of hazardous narcotics and new psychoactive substances (NPS)

Ana Blanco-Rodrigues, Robert Stokes

Proceedings Volume 11869, 1186908 (2021) https://doi.org/10.1117/12.2602356

KEYWORDS: Raman spectroscopy, Psychoactive substances, Tablets, Sensors, Safety, Chemical analysis, Signal processing

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Proceedings Article | 12 September 2021 Presentation

Welcome and Introduction to Conference 11869

Henri Bouma, Robert James Stokes, Yitzhak Yitzhaky, Radhakrishna Prabhu

Proceedings Volume 11869, 1186902 (2021) https://doi.org/10.1117/12.2613735

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Proceedings Article | 20 September 2020 Presentation

Opening Remarks by Conference Chairs

Henri Bouma, Robert Stokes, Radhakrishna Prabhu, Yitzhak Yitzhaky

Proceedings Volume 11542, 1154203 (2020) https://doi.org/10.1117/12.2584113

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Proceedings Article | 24 October 2016 Paper

New capability for hazardous materials ID within sealed containers using a portable spatially offset Raman spectroscopy (SORS) device

Robert Stokes, Mike Bailey, Stuart Bonthron, Thomas Stone, Guy Maskall, Oliver Presly, Eric Roy, Craig Tombling, Paul Loeffen

Proceedings Volume 9995, 999506 (2016) https://doi.org/10.1117/12.2241540

KEYWORDS: Raman spectroscopy, Explosives, Glasses, Opacity, Safety, Luminescence, Silver, Sensors, Psychoactive substances, Cobalt

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Raman spectroscopy allows the acquisition of molecularly specific signatures of pure compounds and mixtures making it a popular method for material identification applications. In hazardous materials, security and counter terrorism applications, conventional handheld Raman systems are typically limited to operation by line-of-sight or through relatively transparent plastic bags / clear glass vials. If materials are concealed behind thicker, coloured or opaque barriers it can be necessary to open and take a sample. Spatially Offset Raman Spectroscopy (SORS)^[1] is a novel variant of Raman spectroscopy whereby multiple measurements at differing positions are used to separate the spectrum arising from the sub layers of a sample from the spectrum at the surface. For the first time, a handheld system based on SORS has been developed and applied to hazardous materials identification. The system - "Resolve" - enables new capabilities in the rapid identification of materials concealed by a wide variety of non-metallic sealed containers such as; coloured and opaque plastics, paper, card, sacks, fabric and glass. The range of potential target materials includes toxic industrial chemicals, explosives, narcotics, chemical warfare agents and biological materials. Resolve has the potential to improve the safety, efficiency and critical decision making in incident management, search operations, policing and ports and border operations. The operator is able to obtain a positive identification of a potentially hazardous material without opening or disturbing the container - to gain access to take a sample - thus improving safety. The technique is fast and simple thus suit and breathing gear time is used more efficiently. SORS also allows Raman to be deployed at an earlier stage in an event before more intrusive techniques are used. Evidential information is preserved and the chain of custody protected. Examples of detection capability for a number of materials and barrier types are presented below.

Proceedings Article | 23 October 2010 Paper

Advances in quantum cascade lasers for security and crime-fighting

Erwan Normand, Robert Stokes, Kenneth Hay, Brian Foulger, Colin Lewis

Proceedings Volume 7838, 78380A (2010) https://doi.org/10.1117/12.871339

KEYWORDS: Quantum cascade lasers, Explosives, Sensors, Explosives detection, Improvised explosive devices, Spectroscopy, Hydrogen, Molecules, Molecular lasers, Infrared radiation

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Proceedings Article | 25 September 2009 Paper

The fusion of MIR absorbance and NIR Raman spectroscopic techniques for identification of improvised explosive materials in multiple scenarios

Robert Stokes, Erwan Normand, Ruth Lindley, Paul Black, Michael McCulloch, David Middleton, W. Ewen Smith, Brian Foulger, Colin Lewis

Proceedings Volume 7486, 74860O (2009) https://doi.org/10.1117/12.830348

KEYWORDS: Raman spectroscopy, Spectroscopy, Explosives, Quantum cascade lasers, Hydrogen, Molecules, Sensors, Absorbance, Near infrared, Raman scattering

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Proceedings Article | 18 September 2009 Paper

Development of a QCL based IR polarimetric system for the stand-off detection and location of IEDs

Robert Stokes, Erwan Normand, Iain Carrie, Brian Foulger, Colin Lewis

Proceedings Volume 7486, 748609 (2009) https://doi.org/10.1117/12.830076

KEYWORDS: Quantum cascade lasers, Cameras, Improvised explosive devices, Quantum well infrared photodetectors, Staring arrays, Absorption, Polarimetry, Sensors, Polarization, Target detection

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Proceedings Article | 19 February 2009 Paper

DPN writing on non-flat gold surfaces and detection by SERS

Robert Stokes, Jennifer Dougan, Eleanore Irvine, Jenifer Ohayon, Sergey Rozhok, Tom Levesque, Bruce Dudzik, Mike Nelson, Duncan Graham

Proceedings Volume 7207, 720703 (2009) https://doi.org/10.1117/12.811523

KEYWORDS: Scanning probe lithography, Surface enhanced Raman spectroscopy, Gold, Raman spectroscopy, Plasmonics, Resonance enhancement, Raman scattering, Chemistry, Fluorescence spectroscopy, Molecules

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Proceedings Article | 13 February 2009 Paper

Functionalised nanoparticles and SERRS for bioanalysis

Duncan Graham, David Thompson, Fiona Mckenzie, Karen Faulds, Ross Stevenson, Andrew Ingram, Robert Stokes, Emma McFarlane, James Alexander, Paul Garside, Axel Huber, Ian McInnes

Proceedings Volume 7192, 719202 (2009) https://doi.org/10.1117/12.810161

KEYWORDS: Nanoparticles, Silver, Gold, Raman spectroscopy, Resonance enhancement, Proteins, Absorbance, Plasmons, Sodium, Raman scattering

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Proceedings Article | 3 October 2008 Paper

Rapid screening and identification of improvised explosive and hazardous precursor materials by Raman spectroscopy

Robert Stokes, W. Ewen Smith, Brian Foulger, Colin Lewis

Proceedings Volume 7119, 71190I (2008) https://doi.org/10.1117/12.800280

KEYWORDS: Raman spectroscopy, Hydrogen, Explosives, Raman scattering, Glasses, Phosphorus, Urea, Semiconductor lasers, Charge-coupled devices, Nerve agents

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Proceedings Article | 29 August 2008 Paper

Single and double stranded DNA detection using locked nucleic acid (LNA) functionalized nanoparticles

Fiona McKenzie, Robert Stokes, Karen Faulds, Duncan Graham

Proceedings Volume 7035, 70350J (2008) https://doi.org/10.1117/12.794965

KEYWORDS: Nanoparticles, Gold, Hydrogen, Silver, Target detection, Resonance enhancement, Temperature metrology, Head, Raman scattering, Surface plasmons

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Proceedings Article | 26 August 2008 Paper

Fabrication of biosensor arrays via DPN and detection by surface enhanced resonance Raman scattering

Robert Stokes, Jennifer Dougan, Eleanore Irvine, Jason Haaheim, Paul Stiles, Tom Levesque, Duncan Graham

Proceedings Volume 7032, 70320W (2008) https://doi.org/10.1117/12.794721

KEYWORDS: Scanning probe lithography, Resonance enhancement, Raman scattering, Chemistry, Plasmonics, Gold, Biosensors, Molecules, Luminescence, Raman spectroscopy

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Proceedings Article | 8 October 2007 Paper

Raman spectroscopy of illicit substances

Robert Stokes, Karen Faulds, W. Ewen Smith

Proceedings Volume 6741, 67410Q (2007) https://doi.org/10.1117/12.739081

KEYWORDS: Raman spectroscopy, Raman scattering, Luminescence, Spectrometers, Metals, Laser scattering, Molecules, Surface enhanced Raman spectroscopy, Hydrogen, Photons

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