Optical Fiber Bragg Grating Filter for Wavelength Division Multiplexing (WDM) Applications

Abstract

A Fiber Bragg grating is an aperiodic or periodic disorder of the effective index of refraction in the optical fiber core, having nanometres range period. For short periods of the index modulation, the disorder in index of refraction perturbation induces the light reflection in a limited wavelength range, for which condition of Bragg is satisfied. Incidence of a broad-spectrum light onto one fiber end containing a fiber Bragg grating, induces reflection of the portion of the light corresponding to wavelength of the Bragg grating to the input end, while the remaining light reaches the other end. Optical wavelength division multiplexing (WDM) networks employed in long distance and metro areas; several nodes are present to distribute the signal. The optical add-drop multiplexer (OADM) is the significant equipment which is responsible for separation of distinct wavelengths and redirection of the linked signals across the network to the corresponding users. The operating principle of the optical add-drop multiplexer deems an accurate filtering operation, provided by Bragg gratings. In this paper, optical fiber Bragg grating filter is designed and analysed for Wavelength Division Multiplexing (WDM) application.