Study On All Fiber Cladding Pumping Ytterbium-Doped Fiber Laser

All fiber cladding pumping fiber laser is a new type luminescence device in recent years and has many applications in optical fiber communication, optical sensor, industry processing, medical treatment and military field because of its excellent performance. Compared with other fiber lasers, cladding pumping technology improves efficiency of pumping source and promotes the development of high performance fiber laser. At present, research and development of fiber laser used in many aspect have become the hotspot of laser field. With the advancement of technology, the high efficiency, long life, small volume and excellent performance fiber laser will replace large volume lasers (such as CO₂ and YAG lasers) and this kind of fiber laser will be the main product of lasers. The research and development of high-performance fiber laser is becoming new key research.In this paper the fundamental principle of cladding pumping fiber laser is introduced. The key technology and processing of cladding pumping fiber laser are also analyzed. We reviewed the development and application respect of cladding pumping fiber laser.We adopt cladding pumping method to provide powerful help in improving performance of fiber laser. We analyzed the performance of cladding pumping fiber laser with different inner cladding structure through the geometry and fiber optics methods. We established the theoretical model and designed the structure of multi-cladding fiber which improves beam quality.Based on rate equations and transmission equations, the analytical model of high power Yb³⁺- doped double clad fiber lasers is developed. By solving rate equations, the expressions of output power, threshold pump power and slope efficiency of line cavity high power fiber lasers are obtained. Based on the analytical model, the effects of fiber length, mirror reflectivity, pump wavelength, laser wavelength and Yb³⁺ concentration on performances of fiber lasers are discussed.Considering the structure of cladding pumping Yb³⁺ doped fiber laser, we designed the fiber grating resonance cavity and analyzed the fundamental characteristics of fiber grating resonance cavity.We established test system of all fiber Yb³⁺ doped fiber laser based on fiber grating resonance cavity and cladding pumping method. The maximum output power is 7.5 W, slope efficiency is 62.6%. Combining the Stimulate Brillion Scatter (SBS), pulse compressing were carried out, optical pulse is 400 ns and compressing factor is 70.The coherent fiber laser and the new fiber laser including fiber embedded structure fiber lasers and double cladding photonic crystal fiber laser are analyzed. We reviewed the fundamental principle and development of these fiber lasers, which provide new idea for high performance cladding pumping fiber laser.In the end, the author summarized the research work and gave the next step plan.