Optical Passive Components

What are Fiber Bragg grating sensors? What are their uses and applications?

Fiber Bragg Grating (FBG) based sensors are one of the most popular optical fiber sensors these days because they are quite easy to install, don’t get influenced by electromagnetic interferences, and can work well even in highly explosive atmospheres. In this blog, we will walk you through what Fiber Bragg grating-based sensors mean and what uses and applications the FBG-based sensors have.

What are Fiber Bragg grating sensors?

Fiber Bragg grating is a small-size optical fiber that consists of a pattern of many reflection points that reflect particular wavelengths in the direction of the light origin and transmit all others. Based on the principle of Bragg diffraction, it is a progressive optical passive component that looks like a normal optical fiber but acts as a sensor that converts energy from mechanical into optical and electrical.                                                                                                                                                                        

FBG sensors are simple optical sensing elements that can be photo-imprinted in optical fibers. These are wavelength modulated sensors that help detect physical parameters such as strain, temperature, pressure, humidity, vibration, and others depending on the changes in the wavelength.

What makes FBG sensors better than their counterparts?

FBG sensors come with many features and qualities that one can’t get from ordinary optical sensors. Some of these are:

  • High sensing capability
  • High stability and reliability
  • Energy-efficient and cost-effective
  • Easy installation and customized length
  • Immunity to electromagnetic interferences
  • Immunity to radio frequency interferences
  • Suitable for highly explosive environments

What is the use of Fiber Bragg Grating sensors?

  • Fiber Bragg grating sensors can be used as inline optical fibers to block certain wavelengths. Apart from this, they can also be used as wavelength-specific reflectors.
  • Since FBG sensors are ideal wavelength-selective components, they can be used where detection of multiple sensing parameters is required.
  • FBG sensors are also widely used for monitoring composites that are subjected to impact.
  • These optical sensors can help measure the internal strain of the host by evaluating the shift in the reflective wave peak’s wavelength.
  • FBG-based sensors when located even too close to impact site can detect residual strains from an impact that C-scan and visual inspection fail to detect.
  • An array of embedded FBG sensors can predict the location of damage as well.
  • FBG sensors are also used for vibration sensing when they are placed intimately in contact with the vibrating object.
  • BG sensors can also help in acoustic sensing of ultrasonic waves not only in bulk materials but also in liquids.
  • These optical sensors have also been used for monitoring ultrasound in vivo.
  • Femtosecond laser-imprinted FBGs are thermally stable, and, thus, are potential candidates for high-temperature sensing applications.
  • These sensors can also be used for intelligent textiles as they can be integrated into flexible orthoses to determine a patient’s requirements and generate feedback.

What are the applications of Fiber Bragg Grating (FBG) sensors?

FBG sensors are the optical passive components that have so much potential to be used in a myriad of applications across different industries. While some applications are widely common, many areas remain yet to be explored when it comes to utilizing the powerful capabilities of FBG sensors.  Some of the common applications of FBG sensors include:

  • ASE filtering
  • Wavelength filtering
  • Environmental monitoring
  • Power line monitoring
  • Structural health monitoring
  • Instrumentation applications, such as seismology
  • Pressure sensors for extreme environments
  • Downhole sensors in oil and gas wells to measure the effects of temperature, external pressure, seismic vibrations, and inline flow measurement

Most FBG sensors are used in single-mode fibers and their modeling is relatively simple. When buying FBG sensors online, do your research properly as FBG sensors are available in a variety of options, and picking the right one is important to achieve the desired performance and functionality.