Erbium-Doped Fiber Laser Based on Fiber Coupler
|School||Shanghai Jiaotong University|
|Keywords||Erbium-doped fiber laser fiber coupler fiber loop mirror (FLM) fiber Bragg grating (FBG) coarse WDM (CWDM) polarization controller (PC) tunable filter narrow band FLM|
Fiber laser has a lot of merits and characteristics, such as good compatibility with fiber components and fiber systems; wide bandwidth; better beam quality and lower noise than semiconductor lasers;in a addition, compact、small volume、portable, and so on. Especially the wavelength of the fiber laser matches with the window of the communication. Fiber laser has good future in fiber communication and fiber sensing and other fields. Fiber laser is regarded as one of the most important components and becomes a hot point over the world.Erbium-doped fiber laser based on fiber coupler has been developed. We have summarized the character, category, the developing level and application of fiber laser. The theoretical model of three-level system of erbium-doped fiber laser has been analyzed. Experiments on two structure of fiber laser have been researched.The creativity in my thesis is the design and fabrication of fiber loop mirror (FLM) based on fiber coupler. First, we used FLM and fiber Bragg grating as the cavity of fiber laser; the stable wavelength can be obtained through wavelength locker. Second, we report a structure of tunable erbium-doped fiber laser based on unsymmetrical narrow band FLM. The resonator is composed of a common FLM and a narrow band FLM which contains a high-birefringence FLM、a polarization controller(PC) and a coarse WDM(CWDM), and by changing the status of the PC in the cavity, the reflection spectrum of the FLM can be adjusted to let the laser operate in only one mode. The virtue of the fiber laser based on FLM is low price and easy to obtain, which have a nice future.