Xiang Guangbiao, Chen Jinbao, Wang Xiaolin, Ye Yun, Zhang Hanwei, Zhang Jiangbin, Hua Weihong
Opt Lett. 2024 Nov 1;49(21):6301-6304. doi: 10.1364/OL.540348.
The photodarkening (PD) and transverse mode instability (TMI) effects are two main factors limiting the power increase and long-term stability of high-power fiber lasers. A prolonged burn-in test for an all-fiber laser oscillator below the TMI threshold was carried out. We observed the PD-induced TMI effects, which manifested as a sudden decrease in the output power due to higher-order mode leakage. After several minutes of exposure to a high-power density 450 nm laser diode (LD), the output power returned to its initial state, significantly enhancing the oscillator's stability. The 450 nm LD probably mitigates the accumulation of thermal effects by inhibiting the photodarkening effect, thus preventing the occurrence of the TMI effects and improving the stability of the oscillator's output power. Our work provides useful guidance for the development of high-stability fiber laser oscillators.
光暗化（PD）和横向模式不稳定性（TMI）效应是限制高功率光纤激光器功率提升和长期稳定性的两个主要因素。对低于TMI阈值的全光纤激光振荡器进行了长时间的老化测试。我们观察到了由PD引起的TMI效应，其表现为由于高阶模泄漏导致输出功率突然下降。在暴露于高功率密度450 nm激光二极管（LD）几分钟后，输出功率恢复到初始状态，显著提高了振荡器的稳定性。450 nm LD可能通过抑制光暗化效应来减轻热效应的积累，从而防止TMI效应的发生并提高振荡器输出功率的稳定性。我们的工作为高稳定性光纤激光振荡器的发展提供了有益的指导。
