New Laser Designed for the Military Reveals Composition of Substances [VIDEO]
A new laser capable of showing what objects are made of could aid military aircraft in identifying hidden dangers, including weapons arsenals, far below.
"For the defense and intelligence communities, this could add a new set of eyes," said Mohammed Islam, a professor of electrical engineering and computer science and biomedical engineering at the University of Michigan.
Made from off-the-shelf telecommunications technology, the system emits a broadband beam of infrared light. And while most lasers emit light of one wavelength, or color, super-continuum lasers like the one the researchers developed give off a tight beam packed with columns of light covering a range of wavelengths invisible to the human eye.
The infrared contains "spectral fingerprinting range," meaning frequencies at which they can detect echoes of the vibrations of the molecules comprising a solid surface. Different substances absorb and reflect different wavelengths, so by shining the new laser on a target and analyzing the reflected light, the researchers can tell the chemical composition of the target.
"A grey structure looks grey in visible light, but in the infrared, you can see not only the shape, but also what's inside it," Islam explained.
At this point, while the military uses spectral fingerprinting to a certain extent, current practices rely on sunlight, which can be a problem at night or on a cloudy day.
Furthermore, while broadband infrared lasers exist, they are far weaker than the one the University of Michigan researchers have developed and continue to develop.
Beyond military applications, the scientists say the device has the potential to aid in today's full-body airport screening technologies.
"Those are imaging devices looking for bumps where there shouldn't be bumps," Islam said. "They're looking for shapes that are odd or different. But they can't see the chemicals in the shapes. That's why you have to take your shoes off. But our laser can detect the chemical composition."
Published in the journal Optics Letters, the study was funded by the Air Force Research Laboratory.