Fault detection and monitoring scheme for passive optical network using fiber Bragg grating

The first part of our study explains simulationally Fault Detection and Monitoring (FDaM) system for Passive Optical Network (PON) based on Filtered Orthogonal Frequency Division Multiplexing (F-OFDM). Two types of FDaM are utilized in the downstream and upstream directions for PON. The copy and check method is suggested to detect errors for fault monitoring systems. The copy of the transmitted signal is sent to the Central Office (CO) for monitoring and generated it by using Chirp Fiber Bragg Grating (CFBG). Additionally, the second part presents and experimentally proves a simple optical time domain reflectometer (OTDR) technique for all passive optical networks (PON) by including array fiber Bragg gratings (AFBGs) that can achieve both fault detection and localization objectives. OptiGrating software was used to create AFBGs; this method allows the fault site to be easily determined among four branches divided into two groups. The OTDR proposed is visualized with the FBG interrogator analyzer. To detect errors, each optical network unit (ONU) is assigned AFBGs with different center reflection wavelengths using a simple technique. This makes them perfect for detecting faults in PONs that have high density and capacity. The experimental OTDR results are in good agreement with the computational results. Thus, the proposed technique offers a full online monitoring solution for PON link fault localization and detection.