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Research On C+l Band Multi-wavelength Fiber Laser

Posted on:2011-07-26Degree:MasterType:Thesis
Country:ChinaCandidate:L ZhangFull Text:PDF
GTID:2198330338483507Subject:Physical Electronics
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The technology of wavelength division multiplexing (WDM) is widely used for the high-capacity fiber-optic network. In order to enhance the communication capacity, WDM transmission system is moving in the direction of increasing channels. Multi-wavelength light source is a core technology in wavelength division multiplexing transmission system. This dissertation is focused on multi-wavelength lasers, which include:1. The theoretical research on C+L band multi-wavelength fiber laser1) A theoretical model for the C+L band multi-wavelength fiber laser is constructed and the feasibility of the model is explained clearly.2) The classical model for the semiconductor optical amplifier (SOA) is given. The static gain saturation in SOAs is numerically simulated. The results of SOA gain versus injected current and the input optical power are analyzed.3) The approach of the spontaneous emission noise is introduced. The graphs of ASE and SOA spontaneous emission photon density are simulated.4) The high-birefringence fiber loop mirror filter is analyzed and the steady output of the fiber laser is simulated.2. Experimental research on C+L band multi-wavelength fiber laser1) For the two cascaded structures which are composed by SOAs, the corresponding multi-wavelength fiber lasers are experimented and the experimental results are compared. The impact to the laser by the current, the peak gain wavelength and the sequence of the cascaded structure is discussed. One of the experiment results is simultaneous lasing of 16 wavelengths with spacing on ITU-grid(100GHz). The output power variation is less than 6 dB and it is basically in the C+L band. Its 3dB width is about 0.23nm. By adjusting the states of polarization controller, these wavelengths can be tuned together over 50GHz.2) One-way feedback signal on the C+L band multi-wavelength fiber laser is experimented. The output power is much flatter and the multi-wavelength number is increased significantly due to the feedback signal. Experiments achieve 27 wavelengths which comply with ITU-T standard interval of 100 GHz. The output power variation is less than 6 dB3) The ratio of the coupler in the laser cavity is changed separately. When the ratio is 60:40, 16 wavelengths are achieved whose output power variation is less than 4 dB.4) A non-pumped erbium-doped fiber (EDF) is added to narrow the line widths of the output wavelengths. During the experiments, 19 wavelengths are achieved whose 3dB line width is reduced to 0.16 nm with the output power variation less than 6 dB.
Keywords/Search Tags:wavelength division multiplexing, semiconductor optical amplifier, multi-wavelength fiber laser, high-birefringence fiber loop mirror, C+L band
PDF Full Text Request
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