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Multi-wavelength Fiber Laser Based On Single Mode Fiber

Posted on:2016-03-19Degree:MasterType:Thesis
Country:ChinaCandidate:C JiangFull Text:PDF
GTID:2308330473455659Subject:Optical Engineering
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With the development of fiber optics, the Multi-wavelength fiber lasers have attracted extensive attention of researchers because of its great value in many fields, such as optical communication system and Wavelength Division Multiplexing(WDM) system. At present, the research of Multi-wavelength fiber laser is mainly concentrated in the number of output lasing lines, output wavelength tunable and the stability of the output spectrum, etc. The experiment research in this paper is mainly aimed at improving the number of output lasing lines and the stability of the output spectrum of multi-wavelength erbium-doped fiber laser(MWEDFL). Two groups of experiment have been designed for comparison, the stability of the output spectrum of one group is improved by changing the kind of inserted fiber, the stability of the other is also improved by changing the structure of laser, but the inserted fiber remains the same.(1)The Multi-wavelength erbium-doped fiber laser based on four-wave mixing(FWM) is compressed. The Multi-wavelength fiber laser based on single mode fiber is adopted, a 5km single mode fiber is inserted into the cavity, the mode competition is compressed by the effect of Self-phase modulation(SPM). The laser has 5 stable lasing lines when the pump power is 300 w, which locate at 1556.9nm, 1557.8nm, 1558.8nm, 1559.7nm and 1560.6nm. The minimal power fluctuation of lasing line which locates at 1559.7nm is 0.08 d B and the maximum power fluctuation of lasing line which locates at 1556.9nm is 3.2d B. A 110 m highly nonlinear fiber take place of the 5km single mode fiber, the mode competition is compressed effectively by the effect of four-wave mixing. The laser has 7 stable lasing lines(above-30 d Bm) when the pump power is 300 w, which locate at 1555.8nm, 1556.6nm, 1557.6nm, 1558.5nm, 1559.5nm, 1560.4nm and1561.4nm. The minimal power fluctuation of lasing line which locates at 1555.5nm is 0.04 d B and the maximum power fluctuation of lasing line which locates at 1556.6nm is 0.17 d B. Compared with previous result, the stability of the output spectrum and the number of lasing lines are improved significantly.(2)The Multi-wavelength erbium-doped fiber laser based on Cross-phase modulation(XPM) is studied. The Multi-wavelength fiber laser based on single mode fiber is adopted, but the length of single mode fiber inserted into the cavity is 2km this time, the mode competition is compressed by the effect of Self-phase modulation as before. The laser has 5 stable lasing lines when the pump power is 300 w, which locate at 1558.5nm, 1559.5nm, 1560.5nm, 1561.4nm and 1562.3nm. The minimal power fluctuation of lasing line which locates at 1560.5nm is 0.03 d B and the maximum power fluctuation of lasing line which locates at 1562.3nm is 4.56 d B. Then the structure of laser is changed by inserting the 2km single mode fiber into a nonlinear optical loop mirror(NOLM),which can produce an enhanced cross-phase modulation and compress the mode competition in cavity effectively. The laser has 5 stable lasing lines when the pump power is 300 w, which locate at 1561.3nm, 1562.2nm, 1563.2nm, 1564.1nm and 1565.1nm. The minimal power fluctuation of lasing line which locates at 1564.1nm is 0.18 d B and the maximum power fluctuation of lasing line which locates at 1561.3nm is 0.61 d B. Compared with previous result, although the number of lasing lines still keep the same, but the stability of the output spectrum is improved significantly.
Keywords/Search Tags:Multi-wavelength Erbium-Doped Fiber Laser(MWEDFL), Four-wave Mixing(FWM), Self-phase Modulation(SPM), Cross-phase Modulation(XPM), Nonlinear Optical Loop Mirror(NOLM)
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