Study On Transmission Performance Of Wdm-pon System Based On Rsoa Re-modulation

Wavelength division multiplexing (WDM) passive optical network(PON) is the future trend of broadband access networks, which can provideeach user virtually almost unlimited bandwidth. Its advantage onmaintenance management, capacity scalability, and information securitymade WDM PON extremely attractive. Most countries have alreadycompleted a long distance fiber optic backbone network deployment, and themajority of them will use WDM technology in the backbone networktechnology. WDM technology can aggregate a plurality of wavelengthsignals on a single optical fiber for transmission, so it can realize thelarge-capacity transmission. However, to the large-scale commercialdeployments, WDM PON is too expensive to have strong competitiveness, soWDM PON’s competitiveness remains to be improved. In particular, whenwe need a high transfer rate and large transmission distance while improvingits cost-effectiveness, then to the WDM PON, the key is to further improvethe transmission rate and the maximum transmission distance (or the splitting ratio).After continuous experimentation and exploration, the WDM-PONsolutions based on reflective semiconductor optical amplifier (RSOA) isemerged. The necessity of suppressing expensive external modulators andoptical amplifiers, using colorless optical network unit (ONU) andbi-directional single fiber system enable the WDM-PON based on RSOA tobe the best choice. So how well the performance of the re-modulationWDM-PON system based on RSOA turns out? With this issue, this paperfocused on the performance of re-modulated WDM-PON system based onRSOA under a series of comprehensive studies. The first is the study of thephysical characteristics of the RSOA, and the impact of RSOA on theamplitude and phase of the upstream re-modulated signals, also theestimation and optimization strategies; Then combine multiple uplinkmodulation schemes, such as NRZ, DPSK, QPSK modulation, research theimpact of re-modulation format on the uplink transmission performance andmake comparison on the those re-modulation format transmission; After that,study the maximum uplink transmission rate of QPSK modulation systemand the maximum transmission distance in the case where the EDFAamplifier is not used; Then, with the analyzing of RSOA frequency responsecharacteristics, do summarize about the system performance about WDM PON based on RSOA under multiple modulation formats, and proposebreakthrough point about above system where system can be improved andbe useful to further research. Lastly, study the physical methods to improve3-dB bandwidth of RSOA, and analysis the performance of RSOA-baseduplink systems using MZI, which can improve system’s modulation rate. Themain things have done by the writer in this article are following:First, systematically studied the international developments ofWDM-PON technology, and its structural characteristics; proposed someproblems existing in the WDM-PON technology and provided some possiblesolutions to deal with these problems; Then, studied the physicalcharacteristics of RSOA, and describe the whole modulation process, thendid estimation of RSOA on the impact of re-modulated signals’ amplitude,phase, etc.; Then, studied the uplink modulation system properties based onRSOA, such as NRZ, DPSK, QPSK modulation schemes, etc., Then analyzedthe relationship between the transmission speed, the distance and themodulation format; Finally, discuss the maximum transmission speed anddistance of QPSK uplink re-modulation transmission with the electronicequalization technology, any amplifier as EDFA is not used, which is basedon direct modulation of RSOA. Then make simple analysis of the effect ofelectronic equalization on the dispersion compensation. Finally with the analyzing RSOA frequency response characteristics, study the physicalmethods to improve3-dB bandwidth of RSOA, and the performance analysisof RSOA-based uplink systems after the introduction of MZI, and theprinciples of improve system’s modulation rate. Then give the detailedtheoretical and comprehensive analysis with experiments.