Study On Tunable Fiber Lasers Suitable For ITU Standard DWDM Optical Communication Systems

DWDM has been an economical and effective approach of the capacity extending and upgrading of optical communication system. As the critical components for optical communication, Fiber Bragg Grating and fiber lasers are widely used in DWDM networks. In this dissertation, we study theory and experiment of fiber lasers with FBG. Theory and methods of wavelength tuning with FBG is also present.Keep to these points, several work is carried out as follows:1. In the second chapter, the framework and theory of fiber laser are present, then the thesis explains the structure of the Er3+, introduce the working principle of fiber laser. Besides, tunable laser is also present in this thesis, including the tunable semiconductor laser, the tunable fiber laser and their sorts and the research situation of every different sort.2. In the third chapter, the thesis starts with the research situation of fiber grating, then after introducing the category, the thesis presents the theoretical analysis of the temperature and stress influence on the FBG's bragg wavelength. At last some methods for wavelength tuning are present and compared.3. In the fourth thesis, the output characteristics are studied theoretically, the best fiber length and the connection between the threshold power and the fiber length are gained. Then we proposed a series of experiment schemes. Er3+ doped fiber ring and line lasers, which are pumped by a laser of 980nm, are realized. Emissing wavelengths are 1538.1nm and 1536.5nm, the output power of 0.76mV, 0.83mV, 0.92mV, 0.94mV are respective achieved. And we also made experiments on tunable and multiwavelength fiber lasers.To sum up,theoretical studies, methods comparing and experiment test of fiber laser with FBG are discussed, and some data is obtained which is useful for the future research.