The Study Of Clock Recovery And Demultiplexing Module In 160Gbit/s OTDM

Compared with the widly used Wave Division Multiplexing System , Optical Time Division Multiplexing System has its own advantages. For example , complex management for wavelength is not needed , and a single light source is needed, etc. at the same time ultra-high speed optical transmission can be achieved by OTDM associated with WDM. So studying high-speed OTDM system is significantly. And clock recovery and demultiplexing module is an important component of the system and has a significant impact on the bit error rate. This paper will focus on 160Gbit/s OTDM system.1,We study the working mechanism of EAM and the principe of the demultiplexer based on EAM. By observation of the sampling window, we can prove that the characteristics of EAM is related to its own model as well as the frequency of the drive singnal. So we use two level structure of EAM to realize the demultiplexer for 160Gbit/s OTDM system . Finally we have observed the result of the demultiplexing experiment and noticed that it would case error bits if the sampling window is unsuitable.2,A detailed noise analysis of a CR circuit based on an E/OPLL. By a small-signal analysis, the Langevin equations describing this system are linearized to an Ornstein-Uhlenbeck process, and the correlation functions are obtained by the inverse Fourier transformation technique.Furthermore, the pdf of the recovered clock signal is computed. By using Khintchin theorem, we can compute the power spectrum of the PLL.3,We have described the influence of first order PMD on the decision times based on clock recoveries for both high-Qfilter-based clock recovery and PLL-based clock recovery. Closed-form expressions relating the PMD-induced sampling time shift with the differential group delay and the power ratio between the principal states of polarization are obtained for each high-Q filter-based clock recovery and PLL-based clock recovery.4,By experimenting, we could verify that we can extract the clock from high-speed OTDM signal by using a feedback loop structure with a slow SDH clock and data recovery module. Moreover, we have tried to do an all-optical clock recovery experiment using cross-gain modulation effect. The results and the reason for failure were analyzed. And some ideal were put forward to improve the experiment.