ABSTRACT
Consider a uniform fiber Bragg grating with grating length Lg and forward-propagating wave incident from z=-8, and no backward-propagating wave for z = Lg/2. A. The bandwidth for a uniform Bragg grating is the measures between the first zeros on either side of the maximum reflectivity. In addition to the properties of the reflectivity spectra, the group delay and the dispersion of the reflected light represent other spectral properties of interest in fiber Bragg gratings. One of important parameters that controls the reflectivity and the spectral shape of the fiber grating is the grating’s average refractive index change where it may cause shift in the center wavelength, assuming that the d distributes uniformly across the fiber core and is nonexistent in the outside region, which is often true due to the lack of photosensitivity of the cladding.
