Army Develops Multiwavelength Laser, Countermeasure
ADELPHI, Md., July 29, 2014 — A new optical system aims to protect soldiers using magnification optics against eye-damaging multiwavelength lasers.
Developed by a team from the U.S. Army Tank Automotive Research, Development and Engineering Center (TARDEC), the device is intended for integration into magnified direct-view optics, such as gunners’ primary sights on battle tanks.
It incorporates laser-protection cells at the focal planes where a laser threat’s energy is focused, the researchers said. The cells were found to absorb and disperse the laser energy, weakening the light and distributing it over a larger area of the retina to minimize eyesight damage.
The SLAD laser system emulates the same type of wavelength-diverse laser that soldiers could encounter on the battlefield. Images courtesy of U.S. Army Research Laboratory/Survivability-Lethality Analysis Directorate.
The system was tested against a laser system developed by the U.S. Army Research Laboratory’s Survivability/Lethality Analysis Directorate (SLAD), which operates on multiple wavelengths and emulates “a worst-case, visible laser threat” that could cause serious optical damage.
“We use this custom laser to pump a dye laser, which we developed in-house,” said SLAD physicist Norman Comer. “Together, they mimic a wavelength-diverse laser. The final output is designed to simulate the postulated threat in terms of its energy, pulse width, beam size and divergence.”
Conventional lasers operate with single wavelengths, which can be blocked with filters, Comer said. This would not be possible for wavelength-diverse lasers without also blocking the entire visible spectrum, he said.
A custom laser is used to pump the SLAD threat emulator.
“Our primary concern is to protect soldiers from eye damage and blindness,” Comer said. “But it is also our goal to give soldiers an advantage in the field by being able to defeat these kinds of threats.”
SLAD researchers also developed a mathematical characterization method to predict the protection cells’ optical cross section based on the size and concentration of particles inside them. The researchers found that the cells’ cross-section arises from multiple wavelength scatters instead of more typical single reflection found in standard focal planes such as glass reticles and detectors. This information will help optimize the protection system, the researchers said.
For more information, visit www.arl.army.mil.
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