Introduction to Fiber Optic Sensing

OFS is a leading manufacturer of optical fibers and cables for demanding sensing applications.  

Fiber optic sensors detect changes in temperature, strain, and other parameters by using the physical properties of light as it travels down an optical fiber. In many instances, the optical fiber itself is the sensor, resulting in thousands of continuous sensor points along the fiber length. This is an ideal way for measuring many different types of conditions and small changes accurately.

Fiber Optic Sensing Applications

The fundamental characteristics of optical fiber and cable, lend themselves to solving real world problems.

  • Imagine being able to monitor the entire length of a water, oil, or gas pipeline to create a temperature profile, ensuring adequate flow.
  • How about listening to that same pipeline to detect small, manageable leaks at any point along the pipe – before they become catastrophic?
  • What if we could sense seismic activity over great areas, using existing telecommunications cables?
  • Is it possible to detect foot traffic, vehicle movement, or intrusion activities along a remote perimeter?
  • Could we reduce the frequency and severity of train derailments by working to detect rail fatigue or break and their causes – preventing, rather responding to them after-the-fact?
  • Why not use a “smart fiber” that is minimally intrusive, virtually weightless, to monitor the dynamic 3D shape of a structure to which it conforms?

Fiber Optic Sensing Technologies

  • Distributed Temperature Sensing (DTS) –DTS measures the temperature profile along the fiber length that extends from the source to the detector by measuring light attenuation induced by temperature changes.  Several research groups have well-characterized the attenuation vs. temperature curve for silica glass over a wide range of temperatures, making it a convenient way to measure temperature profiles inside pipes or other structures.
  • Electricity – Distributed Temperature Sensing (Electrical DTS) – Reliable temperature measurement of high-voltage transmission lines is critical to help secure the rising demand for electricity.  Advanced optical fibers from OFS, integrated in Distributed Temperature Sensors on power lines, help ensure optimal safety and performance in both medium- and long-distance systems.
  • Oil and Gas Distributed Temperature Sensing (Oil and Gas DTS) – Many land and subsea oil operations rely heavily on distributed temperature sensing for improved safety and functionality in these harsh environments. OFS optical fibers help ensure reliable performance and durability in high-temperature, high-pressure, and hydrogen-rich environments.
  • Distributed Acoustic Sensing (DAS) -Distributed Acoustic Sensing utilizes optical fiber to detect acoustic vibration. Sound is detected as if microphones are placed at meter intervals along spans reaching more than 100 km. AcoustiSens® Wideband Vibration Sensor Fibers and Cables are vibration sensing fibers and cables optimized for Distributed Acoustic Sensing (DAS) systems. Using a waveguide design based on the ITU-T G.657.A1 telecom-grade single-mode standard, AcoustiSens Wideband Optical Fibers significantly increase Rayleigh backscatter while maintaining low attenuation to improve Optical Signal to Noise Ratio (OSNR).
  • Oil and Gas – Distributed Acoustic Sensing (DAS) – Optical fibers in Oil and Gas DAS applications allow for near real-time measurements. Featuring low attenuation, long reach, and a dielectric nature (immune to RFI and EMI), optical fiber in DAS creates a long sensor element (up to 50 km) that can detect high-resolution events throughout the entire length of the fiber. Our Ge-doped single-mode and pure-core single-mode fiber type products, in particular, provide a low cost per sensor point.
  • Distributed Strain Sensing (DSS) – In strain sensing, fiber optic cables are engineered and mechanically coupled to structures like dams and pipelines where ground movement can be detected and threatened locations pinpointed.
  • Distributed Strain and Temperature Sensing (DSTS, also called DTSS) – DSTS is used where critical systems of great length can be continuously monitored for temperature and strain to ensure fault-free operation while improving safety.
  • Fiber Optic Navigation Sensing – Fiber optics are used in navigation systems to provide accurate information about location and direction. Aircrafts, missiles, unmanned aerial vehicles (UAVs), and ground vehicles all require advanced optical fiber navigation technology to ensure reliability and safety.
  • Shape Sensing Technology – Shape sensing allows a fiber to be embedded or attached to a surface to monitor dynamic 3D shapes and enable successful minimally invasive surgery, medical instrument guidance, wind energy and gas turbine blade monitoring, oil drill exploration, and undersea defense operations.