We discuss the fundamental limits of fiber Bragg grating (FBG) wavelength metrology. High-accuracy wavelength measurements are critical for FBG strain sensors because a wavelength measurement uncertainty as small as 1 pm leads to an uncertainty of nearly 1. A fiber Bragg grating (FBG) is a type of distributed Bragg reflector constructed in a short segment of optical fiber that reflects particular wavelengths of light and transmits all others. They are easy to install, immune to electromagnetic interferences and can also be used in highly explosive atmospheres. But just how does a fiber Bragg grating work? Our experts answer this and other questions. A variation of the period of the grating inscripted in a fiber optic – induced by mechanical or thermal perturbation – causes a shift of the reflected peak wavelength, due to the related optical path length variation.
[PDF Version]