The development of visible fiber lasers toward increasing power and variety has facilitated their usage in a rapidly growing number of scientific and industrial applications. Until now, holes in the visible spectral region have remained difficult or expensive to fill. Green laser oscillation in Ho³⁺ active fibers has contributed to bridging the so-called “green gap” between readily accessible spectral ranges, which is difficult to access with conventional semiconductor laser sources. However, green fiber lasers are limited in power because of the lack of high-brightness pump sources. Their wavelength tuning capability is also bottlenecked at short emission wavelengths due to the strong signal reabsorption. In this study, we developed a means of continuously tunable laser operation at the true-green wavelength of 535–553 nm. In a free-running laser operation, an output power up to 0.98 W was achieved at a center wavelength of 543.1 nm, yielding a Gaussian-like beam. This represents the highest power level demonstrated to date from a visible Ho³⁺-doped fiber laser. The results enable a new class of broadband green tunable fiber lasers with a power level on the order of watts and beyond, filling in the “green gap”.

中文翻译：

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瓦特级可见连续波上转换光纤激光器朝向 535–553 nm 的“绿隙”波长

可见光纤激光器向着增加功率和种类的方向发展，促进了它们在快速增长的科学和工业应用中的使用。直到现在，可见光谱区域中的孔洞仍然难以填充或成本高昂。Ho ^{3+ 中的}绿色激光振荡有源光纤有助于弥合容易获得的光谱范围之间的所谓“绿色差距”，而传统半导体激光源很难获得这种差距。然而，由于缺乏高亮度泵浦源，绿色光纤激光器功率有限。由于强信号重吸收，它们的波长调谐能力在短发射波长处也存在瓶颈。在这项研究中，我们开发了一种在 535-553 nm 的真绿色波长下连续可调激光操作的方法。在自由运行的激光操作中，在 543.1 nm 的中心波长处实现了高达 0.98 W 的输出功率，产生了类高斯光束。这代表了迄今为止可见的 Ho ^{3+ 所}展示的最高功率水平掺杂光纤激光器。结果使新型宽带绿色可调谐光纤激光器成为可能，其功率水平在瓦特级甚至更高，填补了“绿色空白”。