An underground fiber optic fence
HAIFA, Israel – Tunneling to circumvent
borders could be a thing of the past,
thanks to a fiber optic-based technique developed here. Researchers Dr. Assaf Klar
and Dr. Raphael Linker of Technion, the
Israel Institute of Technology, have devised a system that monitors buried fiber
for the telltale soil displacements associated with tunneling activity.
The technology can detect tunnels many
feet below ground, with the limit dependent upon tunnel size and the distance between fiber and tunnel. “But when the distance is smaller than about 20 meters, the
detection rate is high, regardless of tunnel
size,” Klar said.
The method makes use of Brillouin optical time-domain reflectometry, a fiber
optic strain-monitoring technology that
measures the Brillouin shift of the back-
By monitoring tiny soil displacements along a fiber
optic cable, researchers say they can detect tunneling
performed by smugglers. Image courtesy of Technion,
the Israel Institute of Technology.