Pump Excited-State Absorption at 442 ± 1 nm for Efficient Visible Fluoride Fiber Lasers
Pump Excited-State Absorption at 442 ± 1 nm for Efficient Visible Fluoride Fiber Lasers
复制标题
DOI：
10.1109/jlt.2022.3225325
复制
发表时间：
2023-03
影响因子：
4.7
通讯作者：
Wensong Li;Zhibin He;Anxin Yu;Yulun Wu
中科院分区：
文献类型：
--
作者：
Wensong Li;Zhibin He;Anxin Yu;Yulun Wu
在众所周知的激发态吸收（ESA）过程中，激光跃迁的粒子数反转可以通过涉及较低激光能级的强泵浦ESA来实现。基于各种激光源，泵浦ESA的开发已经从可见光扩展到近红外光谱范围。扩展泵浦ESA的工作波长对掺稀土氟化物光纤激光器的发展具有重要意义。在此，我们报告，大概，泵浦ESA的最短工作波长为442 ± 1 nm的一个有效的连续波可见氟化物光纤激光器。提出了一种新的直接蓝光二极管泵浦方案，并在掺Ho 3+氟化物光纤中进行了验证。利用442 ± 1 nm的蓝光半导体激光器，研究了单波长基态吸收（GSA）和单波长ESA泵浦机制，不仅实现了GSA和ESA对上能级的双填充，而且实现了ESA对下能级的去填充。在750 nm光纤激光器中，当泵浦光功率为442 ± 1 nm时，激光器的斜率效率为50.3%，输出功率为327 mW。这一结果是一个数量级高于先前报道的直接蓝色二极管泵浦的深红色Ho 3+掺杂氟化物光纤激光器。此外，数值模拟结果与实验结果吻合良好。我们的方法代表了蓝色泵浦ESA在可见氟化物光纤激光器中的重大进步，这为蓝色二极管泵浦开辟了新的能力，可用于广泛的未来应用。
In the well-known excited-state absorption (ESA) process, population inversion of the laser transition can be achieved by a strong pump ESA involving a lower laser level. The exploitation of pump ESA has expanded from the visible to the near-infrared spectral range, based on various laser sources. Extending the operating wavelength of the pump ESA is greatly significant for the development of rare-earth-doped fluoride fiber lasers. Herein, we report, presumably, the shortest operating wavelength of pump ESA at 442 ± 1 nm for an efficient continuous-wave visible fluoride fiber laser. A novel scheme for direct blue diode pumping was proposed and demonstrated in an Ho3+-doped fluoride fiber. Utilizing a 442 ± 1 nm blue laser diode, single-wavelength ground-state absorption (GSA) and ESA pumping mechanism were investigated not only for double populating of the upper laser level by GSA and ESA, but also to depopulate the lower laser level by ESA. We report a slope efficiency of 50.3% with respect to the launched pump power of 442 ± 1 nm and an output power of up to 327 mW for a 750 nm fiber laser. This result is an order of magnitude higher than that previously reported for a directly blue-diode-pumped deep-red Ho3+-doped fluoride fiber laser. Moreover, the numerical modeling results were in good agreement with the experimental results. Our approach represents a significant advancement for blue pump ESA in visible fluoride fiber lasers, which opens new capabilities for blue-diode pumping for a wide range of future applications.