Fiber optic transmission distance varies based on fiber type, environmental conditions, and equipment selection. Due to the small core, only one optical mode is allowed to be transmitted. This characteristic enables single-mode fibers to transmit signals over long. Fiber Bragg gratings (FBGs) have, over the last few years, been used extensively in the telecommunication industry for dense wavelength division demultiplexing, dispersion compensation, laser stabilization, and erbium amplifier gain flattening. Radiation absorption creates electronic excited states that are trapped by localized defects for extended periods of time.