Optimization of Uniform Fiber Bragg Grating Reflection Spectra for Maximum Reflectivity and Narrow Bandwidth

Fiber Bragg grating has made a big revolution in telecommunication systems. The existence of fiber Bragg grating is needed when an optical fiber amplifier and filter are used. They can be used as band reject filter or band pass filter for optical devices. The design parameters of the fiber Bragg grating affect the output characteristics of it. The purpose of this paper is to simulate and analyze the spectral characteristics of the uniform fiber Bragg grating (FBG) for achieving maximum reflectivity and narrow bandwidth. This can be achieved by studying the effect of the structural parameters of the uniform fiber Bragg grating such as; grating length and refractive index modulation on the reflectivity and spectral bandwidth of the FBG. The simulations are based on the numerical solution of the coupled- mode equations. The effect of changing the refractive index shape is also considered in this analysis. The simulation results show that the reflectivity of FBG will increase when the grating length and the refractive index modulation increase. Besides, the spectral bandwidth will decrease by the increase of grating length. It will also increase when the refractive index modulation increase. This study deduces that the change ofthe refractive index shape doesn't have any effect on the spectral response of the uniform FBG.