1 武汉理工大学硅酸盐建筑材料国家重点实验室, 武汉 430070
2 武汉理工大学材料科学与工程学院, 武汉 430070
3 贵州省都匀公路管理局, 都匀 558000
为了促进磷石膏的综合利用, 改善水泥稳定碎石的抗裂性能。本文通过磷石膏部分取代细集料制备了一种水泥-磷石膏稳定碎石材料, 系统地分析了材料强度、水稳性能和抗裂性能的影响因素。结果表明, 水泥剂量、磷石膏掺量和集料级配均对水泥-磷石膏稳定碎石材料的强度有较大影响。适当将细集料的质量分数降低5%~10%, 更有利于材料形成骨架密实型结构。磷石膏除了具有细集料的填充作用, 还可以促进膨胀性钙矾石(AFt)晶体生长。磷石膏掺量为8%(质量分数)的水泥-磷石膏稳定碎石泡水养护7 d的强度保持率为73.4%, 水稳性能良好, 与水泥稳定碎石相比, 其7 d强度提高了26.7%, 28 d干缩应变降低了40.3%。在贵州省某二级路进行了工程应用, 试验段检测的合格率为100%, 验证了生产配合比的可行性。
水泥 磷石膏 碎石基层 水稳性能 抗压强度 工程应用 cement phosphogypsum crushed stone base water stability compressive strength engineering application
华中科技大学武汉光电国家研究中心，湖北 武汉 430074
光纤激光器被广泛应用于工业加工、****等领域，其输出的激光能量分布往往呈类高斯型分布，这种光斑直径内的非均匀能量分布在应用于光刻、焊接等方面时往往会影响光斑内沿光斑直径不同位置处加工效果的一致性。因此在实际应用中，对类高斯光束进行匀化整形具有重大意义。相对于传统空间结构的光束整形方法，全光纤结构的光束整形对光纤激光器来说具有结构简单、紧凑型好等优点。通过对历年来各学者研究进展的总结，将全光纤结构的匀化整形技术归类为增加输出激光中的高阶模成分和直接改变基模的能量分布两类，并从这两种方法详细阐述了全光纤结构光束匀化整形技术的研究现状，并展望了全光纤结构光束整形技术的未来发展方向。
光纤光学 光束整形 平顶光束 光纤激光器 激光与光电子学进展
2022, 59(15): 1516021
1 华中科技大学武汉光电国家研究中心，湖北 武汉 430074
2 武汉长进激光技术有限公司，湖北 武汉 430206
采用改进的化学气相沉积工艺结合溶液掺杂技术成功制备了一种低数值孔径部分掺杂纺锤形光纤。该光纤的数值孔径约为0.05，镱离子在纤芯中的掺杂直径比约为77%，光纤两端纤芯和包层的直径分别为25 μm和400 μm，中间部分纤芯和包层的直径分别为37.5 μm和600 μm。搭建976 nm双端泵浦光纤放大器，该光纤最终实现了4.188 kW 的单模激光输出，斜率效率为82.8%，最高功率下的光束质量因子约为1.3，其输出功率的继续提升受限于受激拉曼散射效应。
光纤光学 掺镱光纤 光纤设计 横向模式不稳定 受激拉曼散射 光束质量 中国激光
2022, 49(13): 1315002
华中科技大学武汉光电国家研究中心，湖北 武汉 430074
采用稀土掺杂光纤（又称有源光纤）制成的光纤激光器和光纤放大器具有优异的光学性能，已被广泛应用于太空、核电设施及高能物理设施中。有源光纤对辐照十分敏感，当其处于上述辐照环境时易产生辐致损耗，导致光学性能迅速恶化，因此，提高有源光纤的抗辐照性能十分有必要。本文简要介绍了有源光纤在辐照环境下的应用背景以及面临的问题，并从有源光纤的辐照特性、影响辐照特性的因素和有源光纤抗辐照手段三个方面详细介绍了国内外抗辐照有源光纤的研究进展，最后对抗辐照有源光纤未来的研究趋势进行了展望。
激光光学 稀土掺杂光纤 抗辐照 色心 辐致损耗 光纤激光器 激光与光电子学进展
2021, 58(15): 1516012
Author Affiliations
Abstract
Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China
The radical suppression of the photodarkening effect and laser performance deterioration via loading were demonstrated in high-power Yb-doped fiber (YDF) amplifiers. The photodarkening loss at equilibrium was 114.4 dB/m at 702 nm in the pristine fiber, while it vanished in the -loaded fiber. To obtain a deeper understanding of the impact of photodarkening on laser properties, the evolution of the mode instability threshold and output power in fiber amplifiers was investigated. After pumping for 300 min, the mode instability threshold of the pristine fiber dropped from 770 to 612 W, and the periodic fluctuation of the output power became intense, finally reaching 100 W. To address the detrimental effects originating from photodarkening, loading was applied in contrast experiments. The output power remained stable, and no sign of mode instability was observed in the -loaded fiber. Moreover, the transmittance at 638 nm confirmed the absence of the photodarkening effect. The results pave the way for the further development of high-power fiber lasers.
Photonics Research
2020, 8(3): 03000288
1 华中科技大学 武汉光电国家研究中心，武汉 430074
2 中国科学院西安光学精密机械研究所 瞬态光学与光子学国家重点实验室，西安 710119
掺镱石英光纤是掺镱光纤激光器及放大器的重要基础元件.掺镱光纤性能提升是促进掺镱光纤激光器系统功率进一步攀升的关键.本文回顾了高功率掺镱光纤激光器系统功率攀升情况及功率限制性问题，简述了针对激光功率攀升的瓶颈问题所提出的改善性方案.重点阐述了掺镱光纤制备技术、光纤材料、结构性设计在改善功率限制性方面所取得的研究进展，并对未来掺镱石英光纤的研究及发展趋势进行了展望.
光纤激光器 光纤放大器 掺镱石英光纤 光纤制备 热效应 光子暗化 模式不稳 Fiber lasers Fiber laser amplifiers Ytterbium-doped silica fibers Optical fiber fabrication Thermal effects Photodarkening Mode instabilities 光子学报
2019, 48(11): 1148012
华中科技大学武汉光电国家研究中心, 湖北 武汉 430074
高功率铒镱共掺光纤激光器因具有“人眼安全”和在光纤及大气中的低损耗特性,广泛用于光纤通信、激光雷达、卫星遥感和精密测量中。简要介绍了铒镱共掺光纤及其激光系统的发展历程,着重阐述了其在高功率窄线宽方面的最新研究进展,分析了制约铒镱共掺光纤激光器功率攀升的因素。针对镱波段放大的自发辐射和光纤热效应,分别从光纤材料与结构和激光系统结构两个方面进行优化,以实现更高输出功率的铒镱共掺光纤激光器。
激光器 高功率激光器 铒镱共掺光纤 窄线宽激光器 镱波段放大的自发辐射 激光与光电子学进展
2019, 56(17): 170607
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China
In this work, non-isothermal bleaching of Yb–Li co-doped fiber was investigated. The Yb–Li co-doped fiber was beneficial to reduce the photodarkening-induced excess loss and had no bad effect on the temperature of thermal bleaching (TB). Photodarkened fibers were bleached with different temperature ramp rates. The higher the ramp rate, the higher the complete bleaching temperature. The activation energy of the bleaching of Yb/Al/Li fiber was calculated by fitting, which was similar to that of an Yb-doped fiber. These observations are helpful in revealing the relationship between the mechanism of Li ion co-doping and TB.
140.3615 Lasers, ytterbium 060.3510 Lasers, fiber Chinese Optics Letters
2019, 17(3): 031401
1 College of Life Science and Chemistry, Wuhan Donghu University, Wuhan 430074, China
2 Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Frontiers of Optoelectronics
2018, 11(4): 394–399
Author Affiliations
Abstract
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Ytterbium-doped fibers have become the optimum gain media of high-power fiber lasers thanks to a simple energy structure, which strongly reduces the excited state absorption, and a low quantum defect and a high optic–optic conversion efficiency, which means the low thermal load. In this paper, we take a review of the current state of the art in terms of
doped fibers for high-power fiber lasers, including the development of the fabrication techniques. The research work to overcome the challenges for
doped fibers, which affect the stability of output power and beam quality, will be demonstrated. Direction of further research is presented and the goal is to look for a fiber design, to boost single fiber output power, stabilize the laser power and support robust single-mode operation.
High Power Laser Science and Engineering
2018, 6(3): 03000e40
