Laser-based standoff detection of explosives: a critical review

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Effective explosive detection is critical for security.
• Standoff detection offers enhanced safety by identifying threats from a distance.
• Current technologies face challenges in sensitivity, specificity, and operational environments.

Purpose of the Study:

• To review and assess standoff detection technologies for explosives.
• To focus on trace detection methods, complementing with bulk detection techniques.
• To discuss the requirements and maturity of various detection systems.

Main Methods:

• Review of laser-based trace detection technologies: laser-induced-breakdown spectroscopy (LIBS), Raman spectroscopy, laser-induced-fluorescence spectroscopy (LIF), and infrared (IR) spectroscopy.
• Inclusion of bulk detection technologies: millimetre wave imaging and terahertz spectroscopy.
• Analysis of technologies based on their maturity and testing in realistic environments.

Main Results:

• Laser-based spectroscopy methods show promise for trace explosive detection.
• Millimetre wave imaging is a mature technology for bulk detection.
• A range of technologies, from experimental to field-tested, are available, each with specific applications.

Conclusions:

• Standoff detection technologies, particularly laser-based spectroscopy, are advancing for explosive threat identification.
• A combination of trace and bulk detection methods offers a comprehensive approach.
• Continued development and testing are needed to optimize these technologies for real-world security applications.