According to Michigan State University, bomb detecting lasers might be implemented in the fight against terrorism. The laser-based technique could have substantial applications in monitoring packages and luggage, as they are passing through security checkpoints at airports. Ultimately, researchers believe it could radically improve our ability to detect and address explosive devices, thereby improving homeland security.
In the latest edition of Applied Physics Letters, a Michigan State University chemistry professor, Marcos Dantus, has designed a laser-based system capable of detecting infinitesimal traces of some of the chemicals used in bomb making. The technique is able to scan garments of clothing, as well as a traveler’s luggage, and immediately generates an image of a dubious substance’s location.
Marcos Dantus was also the visionary behind BioPhotonic Solutions, becoming its founder and president. He was born in Mexico, where he received his Bachelor of Arts and Masters of Arts degrees from Brandeis University, before going on to study Femtochemistry during his Ph.D years.
He explains, the pioneering technology actually arose when investigating biomedical imaging techniques. He began to look for additional possible applications, and determined that it was capable of identifying evidence of hazardous chemical substances from a distance of ten meters.
Originally, the laser was being designed for facilitating the pain-free detection of skin cancers, harnessing the power of a series of intermittent pulses to accurately differentiate between molecules of the skin. This procedure exploited the “vibrational signatures” to excite the different compounds, providing enhanced contrast.
As a result, the group, who had joined forces with scientists from Harvard University, were able to develop a novel, label-free method of molecular imaging, which was reliant on stimulated Rama scattering (SRS).
Raman scattering is a phenomenon whereby photons undergo inelastic scattering, when interfacing with different clusters of atoms or molecules, resulting in scattered photons that possess an altered frequency and wavelength to that of incident photons; this differs from the more commonly encountered Rayleigh scattering, where the scattered photons possess an unchanged wavelength and frequency.
Raman scattering can be wielded for the purposes of material differentiation, since the process is dependent upon the type of molecules present within a material, as well as their chemical state.
The bomb detecting device operates using a single laser beam, but with two pulses. The first, primary pulse is transmitted to resonate at specific frequencies of explosive chemicals. One of the pulses is described as a “shadow pulse,” and provides a standard reference point, to which the primary pulse can be compared.
Dantus explains that the laser is unaffected by clothing and luggage material or color, as the two laser pulses are in a perpetual state of balance, unless a hazardous chemical is picked up. He boasts about the advantages of his pioneering laser device:
“Our method has Raman chemical specificity, excellent sensitivity and robust performance on virtually all surfaces.”
The teams funding, as to be expected, was offered by the Department of Homeland Security, Science and Technology Directorate.
Homeland security remains playing a game of cat and mouse with terrorists, who are consistently implementing subversive schemes to circumvent checkpoint security technologies. The latest wave of so-called “body bombs” are a stark reminder of how far terrorist factions are willing to go.
Whether such devices are identified depends upon the age and calibration of a particular metal detector. Many of the latest electric detonators use very small amounts of metal, which is making them particularly difficult to expose. However, implementation of the latest bomb detecting lasers, which search for trace amounts of chemical substances, could prove key in the ongoing battle for homeland security, a move which could radically improve global security from the dangers of extremism.
By: James Fenner