In recent years, high-power Ytterbium-doped fiber lasers are widely used in industry, medical treatment, scientific research, military and other fields due to their advantages of high power, high reliability and high beam quality. However, with the gradual increase of output power, non-linear effects and thermal damage have increasingly become an important factor restricting the development of fiber lasers. They reduce the beam quality of fiber lasers and further increase the output power, hindering the further development of fiber lasers. Therefore, the study of the large mode field, high doping, high beam quality fiber is an urgent need to solve the problem of fiber laser development. Under the guidance of Yang Lvyun, Li Jinyan and Dai Naili, doctoral student Chu Yingbo of Wuhan Optoelectronics National Laboratory Fiber Optic Laser Technology Team (FLTG) made the preparation of Yb3 + -doped quartz glass rods based on borosilicate glass phase separation technology , And then prepare large core double clad fiber. The refractive index profile, Yb3 + absorption, and background loss of this fiber were experimentally tested and demonstrated for its laser performance. The results show that the optical fiber has a core diameter of 30 μm and a cladding of 400 μm. The refractive index of the core is uniformly distributed with a numerical aperture of about 0.09. The absorption of Yb3 + at 5.5 nm / s at 976 nm and the background loss of 0.02 dB / m. The hydroxyl content in the fiber was reduced to 1.06 ppm by the water removal process. The 1071 nm laser output was achieved with a 976 nm semiconductor laser pump with a slope efficiency of 72.8% and an optical fiber length of 2.3 m. The results show that this method has great potential in the preparation of active optical fiber with large core diameter and high doping and complex core structure. On March 15, 2016, the research paper was published in the Optics Letters of the American Optical Society (OSA) under the paper "Yb3 + -doped large core silica fiber for fiber laser prepared by glass phase-separation technology" (Vol.41, Issue 6, pp. 1225-1228 (2016)). This study was supported by the National Natural Science Foundation of China (No.51302092,) project. Figure 1. Pore diameter distribution and SEM image of porous glass rod measured by cumulative nitrogen adsorption. Figure 2. Distribution of Yb3 + / Al3 + in optical fiber. Electron probe analysis Figure 3. Fiber refractive index profile and fiber end view. Figure 4. Laser test schematic Figure 5. Laser slope efficiency and laser spectrum Low Smoke And Low Halogen Extruder Low Smoke And Low Halogen Extruder is a combination of high-speed twin-screw, strong mixing and single-screw low-speed, low-temperature, and weak shear characteristics. It is the first choice for efficient mixing and modification of heat-sensitive and shear-sensitive materials. The low-smoke halogen-free cable pelletizer's unique counter-blow die-cutting hot die head with slide rail, part of the head is cooled by water, and the single screw core is cooled by water. Yields have increased significantly. Screw Extrusion,Low Halogen,Low Smoke Extruder,Low Halogen Extruder Nanjing Juli Chemical Machinery Co., Ltd. , https://www.jlextruder.com
October 14, 2021