双包层光纤激光器温度分布数值分析

A numerical analysis on the distribution of temperatures in the double-cladding fiber laser

光纤内的温升是限制高功率双包层光纤激光器发展的重要因素.本工作在分析热沉积分布的基础上,对双包层光纤激光器的温度分布进行了定量研究,并进一步研究泵浦结构和泵浦方式对光纤温度分布的影响,探讨改善高功率双包层光纤激光器热问题的途径,从而为双包层光纤激光器优化设计提供指导.研究结果表明,双端泵浦的双包层光纤激光器光纤两端的温升显著高于中部的温升,两段温度很高.采用多段非均匀掺杂光纤泵浦结构和侧面泵浦方式可以有效的改善光纤内的温度分布,降低温升.设定每端泵浦功率P0=315W,双端泵浦单段均匀吸收系数光纤、三段和五段非均匀吸收系数光纤时,温度分布数值计算结果表明,光纤纤芯最高温度分别约为:414K、357K和336K,因此,采用多段非均匀泵浦结构可以有效的降低光纤中的最高温度.此外,本研究以3段侧面泵浦为例来研究侧面泵浦方式对温升的抑制作用.总泵浦功率仍设定为630W,温度分布数值计算结果表明,光纤中的最高温度降低到了344K.

Temperature rise is the bottleneck in the development of high power doulble-cladding fiber （DCF） lasers. Based on a numerical analysis of the distribution of beat deposition, the distribution of temperatures in fiber is quantita{ively studied, and the influence of the pumping structure and the pumping method on the distribution of temperature in fiber is also researched. The measurements of improvement of the thermal property of DCF lasers are discussed in this work, which are valuable for the optimization of designs of DCF lasers. In the traditional double-end-pumped DCF lasers, the temperature rise in the two ends of DCF is obviously higher than that in the middle part of DCF. The results of study show that the uneven doped multi segments pumping structure and the side pumping method can efficiently optimize the distribution of temperature and decrease the temperature rise. The pumping power of each end of the double-end-pumped DCF laser is kept at 315 W. The numerical results of the temperature distribution show that, when the gain fiber is one even doped segment, three uneven doped segments and five uneven doped segments, the highest temperature in the fiber is 414 K, 375 K, and 336 K, respectively. Therefore, the uneven doped multi-segments pumping structure can effectively decrease the temperature rise in DCF. The three segments side-pumped DCF laser is studied in this work. The total pumping power is 630 W. The numerical results of the temperature distribution show that the highest temperature decreases to 344 K. Therefore, the side-pumping method can efficiently suppress the temperature rise in DCF lasers.