掺铥光纤激光器的波长调谐特性研究

Numerical Study on Wavelength Tuning Characteristics of Thulium-Doped Fiber Lasers

摘要:

基于简化的二能级激光系统和均匀展宽理论模型,利用原子速率方程和功率传输方程建立了掺铥光纤激光器的理论模型,并以环形腔掺铥光纤激光器为例,通过Matlab编程数值模拟研究了其出射功率和波长调谐范围与腔内损耗、掺铥光纤长度、输出耦合比、泵浦波长和泵浦功率等激光器参量的关系。数值模拟结果表明,降低激光器腔内损耗、提高泵浦激光功率和优化掺铥光纤长度可以提高掺铥光纤激光器的出射功率和增加波长调谐范围,而增加输出耦合比虽能提高激光功率,却减小了波长调谐范围。经过参数优化,在腔内总损耗为3dB、输出耦合比为10%的情况下,通过提高泵浦激光功率和优化掺铥光纤长度,掺铥光纤激光器的波长调谐范围可达528nm(1660~2188nm),高于目前已报道的实验结果。将部分模拟结果与文献报道的实验结果进行对比,较好地证实了模型的准确性。研究工作对于掺铥光纤激光器的设计和发展具有重要的理论参考价值和指导意义。

Abstract:

The theoretical model of thulium-doped fiber laser based on the simplified two-energy laser system and uniform spreading theory model was established, using the atomic rate equation and power transfer equation. Taking the ring cavity thulium-doped fiber laser as an example, the relationship between its output power and wavelength tuning range and cavity loss, thulium-doped fiber length, output coupling ratio, pumping wavelength and pumping power, etc., was investigated through Matlab programming numerical simulation. The numerical simulation results show that reducing the laser cavity loss, increasing the pump laser power and optimizing the thulium-doped fiber length can improve the output power and increase the wavelength tuning range of thulium-doped fiber laser, while increasing the output coupling ratio can improve the laser power but reduce the wavelength tuning range. After parameter optimization, the wavelength tuning range of the thulium-doped fiber laser can reach 528nm (1660~2188nm) by increasing the pump laser power and optimizing the thulium-doped fiber length at a total intra-cavity loss of 3dB and an output coupling ratio of 10%, which is higher than the experimental results reported so far. Some of the simulation results are compared with those experimental results in the literature, and the accuracy of the model is well confirmed. These findings have important theoretical reference value and guiding significance for the design and development of thulium-doped fiber lasers.