Characteristics Of Random Fiber Laser

Random fiber lasers are a new type of laser devices with a mirrorless open cavity, in which weak scattering light is continuously amplified on the transmission process in optical fibers. Unlike traditional lasers, they have many advantages, including stable output, simple structure (open cavity), and spatially incoherent continuous wave. They have many potential development prospects in many applications, such as long-distance fiber communication, the source of photonic crystal, optical coherence tomography (OCT), and fiber Sagnac interferometers. They also provide new models and platforms for nonlinear optics, laser physics, and laser applications. The theoretical and practical studies have attracted more and more attention, become the hot and difficult issue and can be further improved and developed.In this paper, we have a full theoretical and experimental study on the random fiber lasers. First, we propose a scheme, making use of ytterbium-doped fiber lasers to achieve1115nm random fiber lasers with stable, continuous, high output power and high slope efficiency random lasing. And we study the effect of different fiber lengths on the output power, in order to find the optimum fiber length to increase the output power. Second, we focus on the temporal and spectral properties of random fiber lasers, and analyze the pump threshold power. At last, we establish a dynamic model based on generalized Schrodinger equation (NLSE) for full numerical description of spectral properties of random fiber lasers, analyze the impact of various nonlinear effects on spectral properties, master effective methods to control output modes, in order to realize random distributed feedback fiber lasers with lower threshold, high output power, high slope efficiency and controlled modes.