Optimization technology for DCF dispersion compensation based on cascaded fiber Bragg grating

A cascaded fiber Bragg grating (FBG) structure is proposed to reduce the dispersion of optical signals in single-mode fibers. Using the OptiSystem software for simulation, the three compensation schemes (precompensation, postcompensation, and symmetric compensation) of dispersion-compensated optical fiber (DCF) are analyzed, and the results show that the best of the three schemes is the postcompensation structure. For the postcompensation scheme, the influence of the coding method and duty cycle on the system is analyzed, and then the fiber grating is cascaded behind the transmitter to obtain a narrow linewidth of the optical signal and minimize the reflectivity sidelobe, and a chirped fiber grating is connected in front of the receiver to compensate for the dispersion of the channel residue. With or without cascaded FBGs, system performance at different input powers and different transmission distances is discussed. The results show that cascading fiber gratings can improve the performance of the system.