A Dispersion Compensation Structure Based On Dual-cavity G-T Interferometer

Nowadays the optical communication system develops so fast that the compensation of chromatic dispersion, which is not so severe in low speed system, becomes more and more important. It is now restricting the increase of optical system signal speed and the channels. However, the DWDM makes the channels of multiple wavelengths increasing to as many as 320, which means that there will be requirements of compensating dispersion of multi-channel rather than single-channel. The complex structure demonstrated here is a two-stage G-T interferometer, which not only has the same periodical nature as single-stage G-T interference, but also improves dispersion capacity by limiting light reflected inside the cavity. This structure is used for multi-channel dispersion compensation simultaneously, especially for DWDM system dispersion compensation. According to the calculation, one more reflection between these G-T cavities could increase dispersion capacity of complex G-T interferometer by a certain amount. The dispersion properties of such devices will be degraded by a couple off actors, such as unconformity of cavity length and unparallel of the G-T cavities, but the structure of dual-cavity G-T interferometer could be finely designed for multi-channel dispersion compensation.In this dissertation, firstly, the rising, developing, and new application in the dispersion compensation of DWDM is introduced, and so does the importance of some dispersion compensation structures. In the DWDM optical network application, some typical dispersion compensation structures and the research direction are demonstrated. Secondly,a new type wavelength dispersion compensation based on G-T cavity is advanced. The G-T single cavity is the key subassembly, the performance of this dispersion compensation structure is determined by it. The characteristics of G-T single cavity, the relationship between its every parameter, and the optimization of parameters are illustrated. The influence of output beam made by the non-parallelism of multi-cavity G-T interferometer is deduced and researched mathematically. Then, the experiment and test result of the dispersion compensation sample is represented, and the improvement and the extendible application is advanced.