Optical Fibre Sensing Has Moved Beyond Telecom Into Structural Health Monitoring for Infrastructure

The Cable That Was Carrying Data and Is Now Carrying Data About the Structure

Optical fibre, the glass strand whose total internal reflection confines light pulses within the fibre core to carry telecommunications signals at the data rates that internet infrastructure requires, possesses a physical property that the telecommunications industry treats as a minor nuisance and that the structural monitoring industry is building a commercial market around: the backscattered light that every optical fibre continuously produces as a result of the Rayleigh, Brillouin, and Raman scattering of the transmitted light signal by the glass molecules of the fibre core, whose wavelength, frequency, and intensity shifts in response to temperature changes, mechanical strain, and acoustic vibration at the precise location along the fibre where the scattering occurs. By interrogating this backscattered light with the optical time domain reflectometry or optical frequency domain reflectometry instruments that measure the scattering signature along the entire fibre length as a continuous distributed sensor, the distributed fibre sensing system converts an ordinary optical fibre into a sensing array that measures temperature, strain, or vibration at every point along the fibre's length simultaneously, turning the fibre into a dense sensor array whose spatial resolution along kilometres of fibre creates the structural monitoring capability that the discrete sensor arrays of conventional structural health monitoring systems cannot cost-effectively replicate at equivalent spatial density.

The optical fibre sensing market, valued at approximately $4.2 billion in 2026 and growing at over eleven percent annually toward $7.8 billion by 2031, encompasses distributed temperature sensing, distributed acoustic sensing, distributed strain sensing, and fibre Bragg grating point sensor systems whose combined addressable market spans oil and gas pipeline integrity monitoring, offshore and subsea infrastructure, civil infrastructure including bridges, tunnels, dams, and buildings, power transmission cable monitoring, and perimeter security. The infrastructure monitoring application is the segment whose commercial growth is accelerating most rapidly, as the combination of ageing infrastructure in developed economies whose maintenance backlog creates the financial pressure that continuous condition monitoring can reduce by identifying structural deterioration before it creates the catastrophic failures that reactive maintenance addresses at far greater cost, and the expansion of large infrastructure projects in emerging economies whose design-life performance monitoring requirements make distributed fibre sensing integration into construction rather than retrofit the most cost-effective approach.

Luna Innovations and the OFDR Architecture

Luna Innovations, the US fibre optic sensing and measurement company, has built its commercial position in optical fibre sensing around its optical frequency domain reflectometry technology whose millimetre-scale spatial resolution along fibre lengths of up to fifty metres creates the density of strain measurement that composite aerospace structures, wind turbine blade structural monitoring, and medical device fibre sensing require at spatial resolutions that the lower-resolution distributed acoustic and temperature sensing technologies whose kilometre-scale spatial resolution suits pipeline and geotechnical applications cannot achieve. Luna's ODiSI optical distributed sensing interrogator, which measures strain and temperature simultaneously along a sensing fibre at spatial resolutions below one millimetre, creates the structural health monitoring capability for the aerospace and industrial applications whose structural integrity monitoring requires the fine-scale strain distribution mapping that identifies stress concentrations, delamination, and fatigue crack initiation at their earliest detectable stage. Silixa, the UK distributed sensing company, has built its commercial position around the Carina Sensing System whose distributed acoustic sensing capability creates the pipeline integrity monitoring, hydraulic fracture monitoring, and seismic monitoring applications that the XT-DTS distributed temperature and strain sensing product range serves in the oil and gas and geotechnical markets.

The distributed acoustic sensing application, in which the fibre responds to acoustic and seismic vibrations whose signature along the fibre is analysed by the processing algorithms that the DAS interrogator applies to identify specific acoustic events including pipeline third-party interference, leak-induced flow noise, and intrusion detection, has established the most commercially mature infrastructure monitoring application in the distributed fibre sensing market. OptaSense, the QinetiQ subsidiary whose DAS systems are deployed across oil and gas pipelines, railway infrastructure, and border security perimeters, and Fotech Solutions, the DAS company acquired by bp in 2020 whose Helios DAS platform serves oil and gas pipeline integrity and railway monitoring, demonstrate the commercial infrastructure monitoring applications where DAS has achieved the operational reliability and regulatory acceptance that pipeline integrity management programmes and railway infrastructure monitoring standards require.

Bridge and Civil Infrastructure Monitoring

The application of distributed fibre sensing to civil infrastructure monitoring, specifically the monitoring of bridge structural health through fibre installed during construction or retrofitted onto the structure's key load-bearing elements, is receiving increasing investment from infrastructure owners and government transport agencies whose bridge inspection programmes are under pressure to transition from periodic manual inspection to continuous automated condition monitoring. The Forth Road Bridge in Scotland, the Millau Viaduct in France, and the Stonecutters Bridge in Hong Kong are among the major civil structures with installed fibre sensing systems whose continuous strain and temperature monitoring creates the structural health record that asset managers use to track long-term performance trends and identify the anomalies that require engineering investigation before they develop into structural deficiencies.

Top 10 Companies in Optical Fibre Sensing and Distributed Sensing Systems Globally

1. Luna Innovations (ODiSI): US fibre sensing company with OFDR technology providing millimetre-scale spatial resolution for aerospace and industrial structural monitoring; its ODiSI distributed sensing interrogator and its aerospace composite structural health monitoring create the high-resolution distributed fibre sensing commercial leader whose spatial resolution advantage serves the precision structural applications that lower-resolution DAS cannot address.
2. Silixa: UK distributed sensing company with Carina DAS and XT-DTS systems for oil and gas, geotechnical, and infrastructure monitoring; its distributed acoustic and temperature sensing and its hydraulic fracture monitoring in oil and gas create the distributed sensing company whose dual temperature and acoustic sensing capability serves both the reservoir monitoring and pipeline integrity applications.
3. OptaSense (QinetiQ): UK DAS company with pipeline integrity, railway, and perimeter security monitoring systems; its QinetiQ defence technology heritage and its railway and pipeline DAS deployments create the distributed acoustic sensing company whose operational infrastructure monitoring references span oil and gas, rail, and security applications.
4. Fotech Solutions (bp): UK DAS company acquired by bp with Helios DAS platform for pipeline and industrial infrastructure monitoring; its bp ownership and its oil and gas pipeline monitoring deployments create the DAS company whose energy industry integration within bp's infrastructure operations provides the operational scale reference that independent DAS suppliers benchmark against.
5. Omnisens (VIAVI Solutions): Swiss distributed fibre sensing company with Brillouin-based distributed temperature and strain sensing for power cables and pipelines; its Brillouin OTDR technology and its power cable thermal monitoring create the distributed sensing company whose electrical transmission infrastructure monitoring application is growing with the offshore wind and submarine cable infrastructure whose thermal performance monitoring is critical for cable rating management.
6. Proximion (Hexatronic): Swedish fibre Bragg grating sensing company with point sensor arrays for structural monitoring; its FBG sensor manufacturing and its Hexatronic Group integration create the fibre Bragg grating sensing supplier whose point sensor arrays complement distributed sensing in the applications where dense arrays of discrete measurements at specific structural locations are required alongside the continuous spatial coverage of distributed sensing.
7. Yokogawa Electric: Japanese test and measurement company with optical fibre sensing products for temperature and strain measurement; its OTDR instrument heritage and its industrial process monitoring expertise create the Japanese sensing company whose fibre sensing products serve the industrial infrastructure monitoring market in Japanese and Asian industrial facilities.
8. Fiber SenSys: US fibre optic sensing company with perimeter security and structural monitoring fibre systems; its perimeter intrusion detection and its structural monitoring applications create the fibre sensing company whose security application establishes the infrastructure monitoring commercial position that its structural sensing products extend.
9. National Composites Centre (SENSING): UK composites research centre with embedded fibre sensing in composite structures for aerospace and wind energy; its composite structure integration of sensing fibres during manufacturing and its aerospace structural health monitoring research create the research institution whose embedded fibre sensing development informs the aerospace and wind turbine blade structural monitoring products that commercial companies are bringing to market.
10. Sensornet: UK distributed fibre sensing company with ULTIMA DTS and HALO DAS for oil and gas and infrastructure monitoring; its distributed temperature and acoustic sensing and its UK and international oil and gas project references create the distributed sensing company whose product range spans the temperature and acoustic sensing modalities that infrastructure integrity monitoring requires across diverse physical measurement needs.