How industries are using distributed fiber optic sensors

Posted: September 28, 2026

You never know for certain where your operations are going to get in trouble. Engineers can guess at the most likely place a conveyer belt might overheat, an electrical conductor might short, a pipe might leak, or a girder might crack. Sensors at those locations can help head off the most likely disruptions. But, faults can happen in unlikely places: ideally, you want a comprehensive view of what’s happening along the entire length of your assets.

Distributed fiber optic sensors (DFOS) are increasingly giving engineers and operators just such a view. Optical fibers are thin strands of glass about the width of a human hair that transmit light across tens of kilometers. They’re most commonly known for carrying telecommunications signals, but they can also be used as extremely sensitive sensors that can monitor changes in temperature, strain, and vibration across their entire length.

Even subtle changes in temperature and strain in an optical fiber cause small perturbations in the light travelling through it. A processor at one end of the cable can read out those small perturbations to determine what’s changing, how much it’s changing, where it’s changing, and what’s likely causing it.

What’s more, because they’re made of glass and light, fiber optics hold up in extreme environments—like 200° C autoclaves or the inside of pipes carrying corrosive chemicals. They’re also intrinsically safe: because they’re non-electrical, they’re immune to electromagnetic interference and don’t pose ignition risks around volatile chemicals.

Below, we take a look at how fiber optic sensors work and check out examples of how many different industries are increasingly putting them to use.

How do distributed fiber optic sensors work?

Light scatters in different ways in response to vibration, temperature and strain on a fiber. Reading out those changes in the light at one end of a fiber provides data about what’s happening at every and any point across its length. Even across 50km (31 mi) to 100 km (62 mi), fiber optics can locate temperature and strain disturbances at a resolution of less than one meter and discriminate temperature with an accuracy of +/-0.01° C.

AI and machine learning software can also distinguish between different patterns of strain and temperature change to determine what’s causing them. For example, it can distinguish changes in vibration in a pipeline caused by seismic activity, leaks, or even just the footsteps of people walking up to 30 feet away.

Applications of DFOS across industries

The energy sector has been one of the industries to most whole-heartedly embrace fiber optic sensors. It’s deployed them down the depth of oil wells and across the length of pipelines to monitor for leaks and other faults.

But other industries are increasingly employing fiber optics as well. They’re attaching cables to everything from conveyor belts and bridges to electrical transmission lines and pipelines. Here’s how industries are putting fiber optics to use.

Making transportation infrastructure smart

Fiber optics embedded along the length of roads and highways can continuously monitor strain, temperature, pressure, tilt, vibration and even humidity of the road structure along tens of kilometers. They can distinguish different types of vehicles and pedestrians and track how fast and where they’re going.

Unlike sensors stretched across the road at one point, fiber optics along a road’s length can record where and when vehicles are changing lanes to provide information about traffic patterns and even identify road defects or traffic incidents. Researchers have proposed using these real-time readings to create digital twins of entire roadways that predict maintenance and traffic needs.

Fiber optic sensors along railway lines can detect structural faults like faulty welds, dents or cracks in the rail, or soft soil and potential sinkholes by analyzing the vibrations as trains traverse the tracks. They can also detect—and even discriminate between—environmental hazards like rockfalls, tree collapses and landslides.

Fiber optics either embedded in new bridges or retrofitted to their exteriors can help identify microscopic cracks that visual inspections would miss and catch possible structural failures before they occur. Distributed fiber optic sensors have successfully detected sub-millimeter deformations of the joints between the sections of the Heinenoord Tunnel, which extends a highway under the Oude Maas River in the Netherlands.

Distributed temperature sensing is also useful for detecting fires in tunnels or even other large interiors, like warehouses or power cable conduits. The Doha metro uses fiber optic sensors to continuously monitor temperature through tunnels up to 40 km long. Operators can see the real-time temperature across the entire tunnel system at a one-meter resolution.

Monitoring water and chemicals pipelines

Several European water utilities have run fiber optics through the length of their water pipelines, using predictive maintenance company Fluves’ DALI sensor system. The fiber pinpoints the location of leaks, pumps or nearby digging activity through up to 20 km at a stretch. The company says the system works with pipes made from concrete, steel, plastic or iron.

Chemicals companies, like BASF, have also deployed fiber optics throughout their pipeline networks. The sensor monitors moisture along thousands of meters of pipeline to detect spots at risk of corrosion that could be missed by standard inspection techniques.

Calculating the health of transmission lines and renewables

A single optical fiber can monitor multiple wind turbines across lengths of 10 km, detecting changes in strain and vibration, identifying loose bolts and monitoring structural health.

Fiber optics have also been put to use monitoring the condition of power cables. A fiber can monitor the temperature of a power conductor across tens of kilometers, identifying hotspots and pinpointing cable failures and faults. For undersea cables, it can keep track of burial depth and monitor cable movement across the length of the conductor.

In Guangdong, China, researchers have used a single optical fiber to monitor strain across 32km of overhead conductors. Researchers hope that subtle variations in the strain on power cables will help identify and predict damage due to icing, lightning strikes, and other events.

Tracking temperature in manufacturing processes

Manufacturers can make good use of fiber optic sensing for monitoring extended assets, like conveyer belts and busbars, or for processes that involve extreme temperatures and pressures.

The Zeilitz salt production plant in Germany monitors temperature across the length of its conveyor belts so it can catch fires before they start. Unlike traditional sensors, the fiber optics hold up to the corrosive, salty conditions and can detect high temperatures wherever they might occur along the belt.

The German Aerospace Center manufactures large aeronautics parts out of carbon fiber reinforced polymer, which it molds at high temperature and pressure inside an autoclave as large as a small house. Fiber optic temperature sensing allows operators to monitor and control the temperature across the span of the entire mold, giving them a more comprehensive view of temperatures than point sensors or infrared cameras. 

At chemicals plants, the LUNA sensor company has used high-temperature magnetic mounts to affix optical fibers around the exterior of large reactors and gassifiers. The fiber monitors the entire surface to discover whether there are any points where the extreme heat on the inside of the vessels may be leaking out to the surface so it can catch hot spots before they lead to catastrophic failures.

What is the future of fiber optic sensing?

While many industries have found success installing their own dedicated fiber optic sensors, an industrial ecosystem is emerging in which heavy industries are partnering with telecommunications companies in mutually beneficial ways. Industries have discovered that they can read the signals coming off of existing telecommunications optical fibers to monitor infrastructure projects, like tunnels, pipelines and railways. Meanwhile, FLUVES has explored water companies leasing the fiber optic sensors installed through their water pipelines to telecom providers to carry telecommunication signals as well. In Iraq, data center hyperscalers are running fiber optics along oil pipelines as an alternative to undersea cables.

Another exciting possible application is using fiber optics to detect and monitor chemical concentrations across large environments—a technology called distributed chemical sensing. While this technology is still under development, its potential applications are myriad. It could monitor things like groundwater reservoirs, pipelines and mining sites.

Norwegian Geotechnical Institute investigator, Christian Totland, told the Society of Exploration Geophysicists podcast, “You need the collaboration between photonics, environments, chemistry and materials science. And also industry involvement is important in all innovation. There’s potentially a broad range of industrial sectors that could be interested in this type of technology.”

For more information on applications for fiber optic sensing, visit the Fiber Optic Sensing Association (FOSA).