In war zones, at airport security screening, around oil refineries, in manufacturing facilities—the list of hazardous environments or potential danger reflects the nature of the modern world. Fortunately, threat detection techniques using optical sensing technologies are being developed to meet safety and security needs in these diverse situations. Our cover story, for example, is about a single-beam stimulated Raman scattering technique under development at Michigan State University that can detect and identify traces quantities of explosives at 1–10 m standoff distance on a variety of substrates (see page 15).
Techniques for threat detection also include Fourier transform infrared spectroscopy, Raman spectroscopy, and thermal imaging. Some require large or prohibitively expensive equipment, are susceptible to fluctuations in ambient conditions, have a weak signal, or involve laser sources that are not eye-safe. In this issue, researchers at M Squared Lasers describe a laser-based hyperspectral imaging technology that addresses these concerns. Initial development has been aimed at detecting and identifying deposits of chemical warfare agents on surfaces, but such a hyperspectral imaging system also could be used to identify substances of interest in oil and gas production, mining, food and drink processing, and forensics (see page 28).
Fingerprints are a valuable forensics tool for law enforcement, and for preventing identity theft and securing buildings. Researchers at Tel Aviv University contributed an article describing a portable low-coherence holography system for 3D fingerprint images, which should further broaden the number of potential applications (see page 54).
As this issue demonstrates, personal and societal security remains one of the greatest values supported by photonics.
Conard Holton
Conard Holton has 25 years of science and technology editing and writing experience. He was formerly a staff member and consultant for government agencies such as the New York State Energy Research and Development Authority and the International Atomic Energy Agency, and engineering companies such as Bechtel. He joined Laser Focus World in 1997 as senior editor, becoming editor in chief of WDM Solutions, which he founded in 1999. In 2003 he joined Vision Systems Design as editor in chief, while continuing as contributing editor at Laser Focus World. Conard became editor in chief of Laser Focus World in August 2011, a role in which he served through August 2018. He then served as Editor at Large for Laser Focus World and Co-Chair of the Lasers & Photonics Marketplace Seminar from August 2018 through January 2022. He received his B.A. from the University of Pennsylvania, with additional studies at the Colorado School of Mines and Medill School of Journalism at Northwestern University.