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Research Of Dynamic Chromatic Dispersion Monitoring Technique In 40Gbps Fiber Communication Systems

Posted on:2006-07-17Degree:MasterType:Thesis
Country:ChinaCandidate:Y LiFull Text:PDF
GTID:2178360182475123Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
Nowadays dynamic tunable chromatic dispersion (CD) compensation has become a key technique in 40Gbit/s and beyond optical fiber communication system. Thus a simple structured and effective chromatic dispersion monitoring method is required. In such a monitoring system the value of chromatic dispersion should be measured,and the feedback signal is acquired to control the tunable CD components in the system. A method to measure dispersion feedback signal is proposed in this thesis. To achieve the real-time monitoring of CD in the optical fiber transmission line, the electrical power of a specific narrow frequency band of a certain optical signal pulse is measured as a feedback signal. In the 40Gbit/s optical fiber communication system used in the experiment, the maximum detectable CD of 130ps/nm and a resolution of 5.2ps/nm were achieved at the narrow band frequency centered at 12GHz. This thesis mainly focuses on the following aspects: 1. From a theoretical viewpoint, the influence of CD on the pulse shape and the spectrum of Gaussian pulses are analyzed. Simulation is performed to analyze the Gaussian pulses in time and frequency domains under different chromatic dispersion conditions. 2. Several reported methods to measure dynamic CD compensation feedback signal are discussed. The pros and cons of each method are analyzed. 3. The equation about the electrical power spectrum and the dispersion value of the Gaussian pulses detected by the photo detector is discussed. The relationship between CD and the electrical power spectrum density at different frequencies was acquired with theoretical analysis and simulation. Furthermore, other factors that affect the electrical power are also analyzed. 4. The experimental structure used to monitor the CD feedback signal using electrical power method is proposed. A CD emulator and a 40Gbit/s RZ code CD detection system were designed and implemented accordingly. 5. Experiments were carried out to test the CDs with 40Gbit/s and 10Gbit/s RZ pseudo-random code optical pulse as the input sequences. The experimental results are in accordance with the theoretical values.
Keywords/Search Tags:dynamic CD compensation, CD monitoring, electrical power method
PDF Full Text Request
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