Fiber Bragg grating

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. This is achieved by creating a periodic variation in the refractive index of the fiber core, which generates a wavelength-specific dielectric mirror.Hence a fiber Bragg grating can be used as an inline optical fiber to block certain wavelengths or it can be used as wavelength-specific reflector.