Fiber Bragg Grating (FBG) based optical fiber sensor technology enable one to measure temperature, pressure, strain etc. at a point or on several points along several hundreds of meters optical cable. A grating can be written at known length where temperature, pressure, strain or vibration whether critical are need to be determined. Its features are- it has advantages over conventional point sensors and strain gauges; and suitable for structural health monitoring applications.
Fiber Bragg Grating (FBG) is a type of distributed reflector that reflects a particular wavelength of light and transmits all other. This is done by adding a periodic variation to the refractive index of the fiber core.A shift in wavelength is observed when temperature or strain around grating is changed. When light is passed down the optical fiber the reflected shift in wavelength is detected and corresponding temperature, pressure or strain changed is observed.