Fiber optic cables are being repurposed as advanced environmental sensors through Distributed Fiber Optic Sensing technology to detect vibrations, temperature changes, and structural strain along up to 80 kilometers of cable with meter-level precision.
With Distributed Fiber Sensing (DFS) technology passive infrastructure can be transformed into a monitoring system to identify threats through in-depth analysis of light backscatter changes.
Threats identification, ranging from anchor strikes on subsea cables to perimeter intrusions of wildfires, will create a vast “nervous system” for foundational infrastructure protection.
Once seen only as pathways for internet traffic, fiber is now doubling as a tool for safety and insight. The transformation is unlocking new opportunities for telcos and giving governments, alongside businesses, smarter options for protecting their infrastructure.
Tech Behind Fiber Optic Sensing
The concept takes advantage of optical time domain reflectometry (OTDR), a method that has been employed for decades to test the health of fibers. But instead of searching for faults only, engineers now examine how light scatters to detect environmental changes.
The fiber itself is a distributed sensor with several different capabilities, Bausor mentioned. This can detect temperature changes, strain, or vibrations, and opening doors to fiber infrastructure monitoring in industries.
These tools can be used as a distributed fiber optic sensing, picking up footsteps, vehicles, or digging near cables. This visibility transforms the fiber into not just an information carrier, but an unseen guardrail for critical services that are not noticed until there are problems.
To Stuart Bausor, who leads the fiber sensing team at Viavi Solutions, the potential is huge.
“If 5G is the neural conduction of the digital age and AI the super brain, fiber sensing serves as the quietly growing peripheral nerves,” Chinese researchers wrote in IEEE ComSoc Technology News last month.
Expanding Uses
Real-world uses for fiber optic sensing solutions are growing exponentially. Perhaps the most useful is protecting subsea cables, through which more than 99% of global internet traffic is routed.
According to Bausor, vibrations in the water can be detected for kilometers, alerting vessels to an anchor strike before it occurs. Offshore wind farms – plagued by cable faults – are another sector turning to digital solutions.
In Chicago, transport authorities are trying to create a distributed acoustic sensing system to detect intrusions or objects on railway tracks. Icelandic scientists even used dormant cables for volcanic early warning.
Scientists are also trying out wearable devices embedded with optical fibres for health monitoring, showing how photonic sensing can find applications beyond infrastructure in medicine. It also incorporates distributed temperature sensing (DTS) to detect fire hazards or stress on buried cables.
When paired with acoustic sensing technology, it provides a multi-layered perception of environments that were previously invisible. A single limitation remains; systems work more effectively with an extra line to play with.
Such dark fiber applications amount to dedicating a cable to sensing fully, though coexistence with live traffic is an ultimate goal. Businesses see the benefit of sensing in outage prevention, increased safety, and millions saved in repairs even with the added expense.
On the other hand, markets are reacting quickly. Grand View Research estimated the worldwide market was worth $1.5 billion last year and is projected to reach $2.8 billion by 2030.
As Bausor pointed out, “sensing is at the forefront” of the needs of numerous industries for real-time network monitoring and more secure operations. Governments, utilities, and data centers are taking a closer look, buoyed by the potential for transforming a humble cable into a multifunction safety network.
With that much fiber in the ground already, the push to render it an intelligent fiber network may turn cables into a global nervous system, one that protects as much as it connects. The way ahead is that fiber optic distributed acoustic sensing may soon be as important as information itself, bridging communication and protection in ways not yet realized.
Inside Telecom provides you with an extensive list of content covering all aspects of the tech industry. Keep an eye on our Telecom sections to stay informed and up-to-date with our daily articles.