Font Size: a A A

All-optical Wavelength Conversion Based On Semiconductor Optical Amplifier Basic Research

Posted on:2013-06-05Degree:MasterType:Thesis
Country:ChinaCandidate:T X XuFull Text:PDF
GTID:2248330374485832Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
The development of communication network is very fast, the overall transmissionrate in a single fiber has been increased to69.1Tbit/s. However, in the nodes of opticalcommunication network, the signal has to be processed in electric domain through theoptical-to-electrical-to-optical conversion. Due to the limit of electron velocitybottleneck(40Gbit/s), there is a serious mismatch between the small data throughput ofnetwork nodes and the huge transmission bandwidth of fiber. In order to improve theinformation processing speed, the electrical node must be replaced by the optical nodein the future optical network. All optical wavelength conversion is a key technology tosolve the wavelength competition and achieve the wavelength re-use and non-blockingwavelength routing in the future optical network. Since semiconductor optical amplifier(SOA) has lots of advantages such as large nonlinear coefficient, small size, ease ofintegration, etc, SOA-based all-optical wavelength conversion has a huge advantagecompared to other methods, and becoming the research focus of today’s academia.Based on the basic transfer equation and the carrier rate equation in SOAs,simulation and experimental results of all-optical wavelength conversion based oncross-gain modulation effect in SOAs have been demonstrated in this thesis.Wavelength conversion of40Gbit/s RZ signal has been achieved in the simulation;12.5Gbit/s NRZ signal wavelength conversion has been realized in the experiment afterthe experimental platform had been built. In the bit-error-rate measurement, the powerpenalty is3.67dB when the BER is10-9. As a key point in wavelength conversion, thespeed restraint of all-optical wavelength conversion due to the slow recovery of SOA’sgain has been analyzed, and a brief analysis about the factors which can affect the resultof wavelength conversion has been given. Besides, to explore the unconventionalphenomena discovered in experiment, a lot of verification experiments and analysishave been carried out. Then we give the possible explanations and potential applicationsof this unconventional result.For improving the speed of wavelength conversion, the wavelength conversionbased on cascaded SOA structure has been proposed as an optimization scheme. Dynamic characteristics of the second SOA is used to compensate for the first SOA’sslow gain recovery, so that the rising time of the output signal could be shortenedgreatly and the speed of wavelength conversion could be increased significantly. Finally,the feasibility of the scheme was verified in simulation and experiment. The resultsshow that the recovery time of the output pulse’s rising edge has been shortened by80picoseconds comparing to wavelength conversion based on cross-gain modulation effectin a single SOA. As a result, this scheme could greatly improve the speed of wavelengthconversion.
Keywords/Search Tags:all-optical signal processing, all-optical wavelength conversion, semiconductor optical amplifier, cross-gain modulation effect
PDF Full Text Request
Related items