Design Of High-count-channel Fiber Bragg Grating Dispersion Compensator

More and more researchers are paying attention on fiber gratings because its unique excellent property, electrically passive operation, high sensitivity, small configuration, lower weigh, multiplexing, and low insert loss. Especially lately twenty years, a lot of financial ability and manpower have been dived by government, so that the study of fiber gratings have greatly development, and have been applied in society. Simultaneity Superstructure FGB and Chirp FGB have been designed. However conventional design approaches have much disadvantage, especially when they are use to design high count channels grating dispersion compensator,for example: asymmetric reflectivity,large amplitude of the index modulation,unclear design and so on.Firstly, we compare our dispersion compensation scheme to other classical scheme, and find the former's unique excellent properties. Whereafter we simulate some typical gratings, and compare our simulated result to authoritative date. It proved that our simulated results are accurate .At one time, we analyze Phase Shifed FGB and Superstructure FGB, and deduct the relation between insert phase and bandwidth. Finally we find the method which design Superstructure FGB have so many disadvantages.To get over this defects, we introduce a novel design approach, which is called discrete layer peeling(DLP).We analyzed its principle and process in detail and simulate the corresponding results.Many grating dispersion compensators were designed by DLP. One of this ,a nine channels compensator work well when it is used to compensate dispersion in a wide range.And this compensator have uniform channel's reflectivity,high isolation rate,low ripple .Finally we find that there are some defect in DLP process.To perfect this approach ,we analyzed its principle,find the method to perfect it and gain the minimum of amplitude of the index modulation. Optimizing phase of channels by GA, we greatly reduce the amplitude of the index modulation, and gained a compensator which have 50 channels can cover with C wave land.However this approach should to develop. When design a high count channels grating which compensate different dispersion channels. The amplitude of the index modulation too complex to realize.