Fiber optic sensing network is a tendency for many applications. It supports a large number of sensors in a single optical fiber with high-speed, high security, and low attenuation. This article provides some information about fiber optic sensing networks.

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Fiber optic sensing network is a tendency for many applications. It supports a large number of sensors in
a single optical fiber with high-speed, high security, and low attenuation. This article provides some
information about fiber optic sensing networks.
What is Fiber Optic Sensing Network?
A fiber optic sensing network detects changes in temperature, strain, vibrations, and sound by
using the physical properties of light as it travels along an optical fiber. The optical fiber itself is
the sensor, resulting in thousands of continuous sensor points along the fiber length.

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How Does Fiber Optic Sensing Network work?
A fiber optic sensing network works by measuring changes in the backscattered light inside of the
fiber when it meets temperature, strain, and vibration.
Rayleigh scattering is produced by fluctuations in the density inside of the fiber. Raman scattering
is produced by the interaction with molecular vibration inside the fiber. The intensity of
anti-Stokes rays is mainly dependent on temperature. Brillouin scattering is caused by the
interaction with sound waves inside the medium. The frequency is dependent on strain and
temperature.
Operating Principle of Fiber Optic Sensing Network
 Optical Time Domain Reflectometry (OTDR)

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In the OTDR principle, a laser pulse is generated from solid-state or semiconductor lasers and is
sent into the fiber. The backscattered light is analyzed for temperature monitoring. From the time
it takes the backscattered light to return to the detection unit, it is possible to locate the location
of the temperature event.
 Optical Frequency Domain Reflectometry (OFDR)
The OFDR principle provides information about the local characteristics of temperature. This
information is only available when the signal is backscattered in the function of frequency. It
allows for efficient use of available bandwidth and enables distributed sensing with a maximum
updated rate in the fiber.
Fiber Optic Sensing Network Technologies
1. Distributed Temperature Sensing (DTS): DTS uses the Raman effect to measure temperature
distribution over the length of a fiber optic cable using the fiber itself as the sensing element.
2. Distributed Acoustic Sensing (DAS): DAS uses Rayleigh scattering in the optical fiber to detect
acoustic vibration.
3. Distributed Strain Sensing (DSS): DSS provides spatially resolved elongation (strain) shapes
along an optical fiber by combining multiple sensing cables at different positions in the asset
cross-section.
4. Distributed Strain and Temperature Sensing (DSTS): DSTS uses Brillouin scattering in optical
fibers to measure changes in temperature and strain along the length of an optical fiber.
5. Electricity DTS: Reliable temperature measurement of high-voltage transmission lines is
essential to help meet the rising electricity demand. Fiber optic sensing, integrated into
distributed temperature sensors on power lines, help ensure optimal safety and performance

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in both medium- and long-distance systems.
6. Oil and Gas DTS : Many lands and subsea oil operations rely heavily on DTS for improved
safety and functionality in harsh environments. Fiber optic sensing ensures reliable
performance and durability in high-temperature, high-pressure, and hydrogen-rich
environments.
7. Oil and Gas DAS: The optical fiber in DAS creates a long sensor element that can detect
high-resolution events throughout the entire length of the fiber.
8. Fiber Optic Navigation Sensing: Fiber optics are used in navigation systems to provide
accurate information about location and direction. Aircraft, missiles, unmanned aerial vehicles
(UAVs), and ground vehicles require advanced optical fiber navigation technology to ensure
reliability and safety.
9. Fiber Optic Shape Sensing Technology: Reconstructs and displays the entire shape of optical
fiber in 2D and 3D. The technology enables cutting-edge applications such as robotic,
minimally invasive surgery, energy, virtual Reality (VR), etc.
10. Wavelength Division Multiplexing (WDM) Technology: Use of Fiber Bragg Gratings (FBGs)
with different reflection wavelengths (Bragg wavelengths) in one optical fiber.
Applications
A fiber optic sensing network is used to monitor pipelines, bridges, tunnels, roadways, and
railways. Also, it is used in oil & gas, power and utility, safety and security, fire detection, industrial,
civil engineering, transportation, military, smart city, minimally invasive surgery, internet of thing
(IoT), etc.

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Conclusion
A fiber optic sensing network has high bandwidth, security, and stability, is immune to
electromagnetic interference, and is lightweight, small in size, and easy to deploy. Sun Telecom
specializes in providing one-stop total fiber optic solutions for all fiber optic application industries
worldwide. Contact us if any needs.