中文摘要：

随着大功率掺铥光纤激光器（TDFL）的广泛应用及其相关技术的迅速发展,多芯TDFL受到了广大研究者的广泛关注,其中有效的包层泵浦技术是实现多芯TDFL高功率输出的决定因素。TDFL通常采用波长为793 nm的激光进行泵浦,通过不断优化工作在793 nm波长的双包层光纤的结构,对其中传输的高斯光束进行整形,当纤芯尺寸为6μm,环尺寸为6.5μm且内包层折射率为1.462 4时,最终获得了合适暗斑尺寸和环状光束宽度的中空光束。利用所设计的双包层光纤泵浦多芯TDFL,可使多芯光纤内掺杂的铥离子更好的吸收泵浦光,提高工作于2μm波段多芯TDFL的输出激光功率和泵浦效率。

英文摘要：

With the wide application of high power Thulium-doped fiber laser （TDFL） and the rapid development of related technologies, multi-core TDFL has received extensive attention from many researchers, and the effective clad pump technology is the decisive factor to realize the multi-core TDFL high power output. TDFL is usually pumped by 793 nm laser. By continuously optimizing the double clad fiber structure at 793 nm operation wavelength, the transmitted Gaussian beam is shaped. When the core size is 6 μm, the ring size is 6.5 μm and the inner clad refractive index is 1.462 4, the hollow beam with suitable dark spot size and circular beam width is obtained finally. Using the double clad fiber pumped multi-core TDFL design, the pump light can be better absorbed by the thulium ions doping within multi-core fiber and the output laser power and pumping efficient of the multi-core TD- FL at 2 μm are improved.