Research On Dynamic Model And Simulations Of Erbium-Doped Fiber Lasers

With the rapid development and applications of rare-earth doped fiber and the DWDM technology in optical fiber communications, Optical Fiber Lasers with various novel structures became a hot and key research field in optoelectronic devices. Due to the advantages of matching with the optical fiber systems, potential narrow width, high output power, and wavelength tunability, optical fiber lasers would find more and more application in future high-speed and long-haul fiber DWDM communication systems.In this thesis, the status and progresses of fiber laser are introduced and the configuration and principle of existing EDFLs were analyzed and discussed, based on this, Erbium-doped fiber lasers based on Hi-Bi fiber Sagnac Loops were deeply studied in details. The major works and results obtained are as following:1. Mainly focus on and discuss the properties of Erbium-doped fiber, the energy level diagram generated by Er 3+ and pump light were demonstrated, the contribution of pump in different wavelength were also analyzed.2. As the researched Erbium-doped fiber laser used Hi-Bi fiber Sagnac loop as the feedback device, the theory of the optical characteristics were demonstrated in detail; the result provided by simulation were carefully discussed and analyzed. In order to better analyze the influence, different values of the parameter in polarization controller, Hi-Bi fiber and coupler were used in the simulation and results has been studied.3. We analyzed the theory of the rate equation, the gain threshold resonance condition and angle resonance condition of the fiber laser, other key performance parameters were also discussed, e.g. the absorption and emission spectra of the Erbium-doped fiber, the life-time of optics in the resonant, etc. 4. Based on the above theory analysis, a dynamic model of Erbium-doped fiber laser based on Hi-Bi fiber Sagnac Loop were established, numerical methods are used to analyze the graph of particle concentration and output laser power per time, and to calculate both the reflection spectra and laser power spectra.5. In the last part of the thesis, we discussed the further potential research based on the current job we've accomplished as well as the research and development trends in future for the EDFL in optical fiber communication system.