强激光与粒子束
2022, 34(12): 123001
1 中南民族大学电子信息工程学院,湖北 武汉 430074
2 中南民族大学智能无线通信湖北省重点实验室,湖北 武汉 430074
本文提出一种使用立方相位光栅测量涡旋光束高阶轨道角动量(Orbital Angular Momentum, OAM)模式的方法。将艾里光束特有的相位变化特性与光栅的结构函数结合,设计一种立方相位光栅,并将涡旋光束准直入射至立方相位光栅的不同入射点上以产生衍射图。数值仿真和实验结果表明,通过分析衍射图中的类厄米-高斯衍射图样可以较容易地测量入射光束的OAM模式。入射光束拓扑荷值的大小由衍射图中的亮条纹数决定,其正负值由亮条纹的分布走向决定。优化后的实验链路可简化实验操作,效果明显,可将检测的拓扑荷值最高可达到60。
光栅 轨道角动量 涡旋光束 空间光调制器 激光与光电子学进展
2021, 58(17): 1705003
Author Affiliations
Abstract
1 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
4 Key Laboratory of Science and Technology on High Energy Laser, CAEP, Mianyang 621900, China
A low-threshold Raman effect in a kilowatt ytterbium-doped narrowband fiber amplifier system is reported. The Raman Stokes light at 1120 nm is achieved with the total output power of only ~400 W, indicating that the Raman threshold of this kilowatt codirectional pumped continuous wave fiber amplifier is much lower than the predicted value estimated by the classic formula. To figure out the mechanism of this phenomenon, simulations based on the general stimulated Raman scattering (SRS) model are analyzed indicating that the key factor is the coupling between four-wave mixing (FWM) and SRS. The simulation results are in good agreement with our experiments.
190.0190 Nonlinear optics 140.3510 Lasers, fiber 190.5650 Raman effect 190.4380 Nonlinear optics, four-wave mixing Chinese Optics Letters
2016, 14(1): 011901
Author Affiliations
Abstract
1 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Department of Space and Command, Academy of Equipment, Beijing 101416, China
The stimulated Brillouin scattering (SBS) threshold affected by repetition rate and pulse duration in a single-frequency nanosecond pulsed fiber amplifier is studied. The experimental results demonstrate that the SBS threshold can be improved either by reducing the repetition rate or by narrowing the pulse duration; however, the average power may be limited in some cases. Otherwise, two evaluation methods for the SBS threshold in the fiber amplifier are compared and discussed, aiming to obtain a more accurate description for the SBS threshold in our single-frequency amplifier system.
140.3538 Lasers, pulsed 140.3280 Laser amplifiers 060.4370 Nonlinear optics, fibers 190.5890 Scattering, stimulated Chinese Optics Letters
2016, 14(3): 031403
Author Affiliations
Abstract
Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
We report on a spectral beam combination of five narrow-linewidth fiber amplifiers. The five-channel output beams are combined in both the near and far field using a polarization-independent diffraction grating that mainly preserves the beam quality of the individual amplifiers. Each amplifier contains a two-stage preamplifier and a main amplifier delivering about 240 W of optical power, which allows a total combined output power of 1.23 kW with an efficiency of over 95%.
Chinese Optics Letters
2015, 13(Suppl): S21415
1 中国科学院上海光学精密机械研究所上海市全固态激光器与应用技术重点实验室, 上海 201800
2 中国科学院大学, 北京 100049
搭建了一个全光纤主振荡功率放大(MOPA)近衍射极限输出的超荧光源,线宽为亚纳米量级,最大输出功率为1509 W,输出斜率效率达到85.2%,光束质量因子稳定在M2=1.4。后向回光功率与输入功率呈线性关系,系统很好地抑制了受激布里渊散射(SBS),并且对环境具有很好的抗干扰能力。在整个输出功率范围内,没有观察到自脉冲和弛豫振荡现象。
激光器 光纤激光器 掺镱光纤放大器 放大自发辐射 光纤布拉格光栅 中国激光
2015, 42(12): 1202009
1 中国科学院上海光学精密机械研究所 上海市全固态激光器与应用技术重点实验室,上海 201800
2 中国科学院大学, 北京 100049
复合环形腔被动相干合成技术是提高激光功率并保持良好光束质量的有效手段。本课题组对该技术进行了理论和实验研究,其中主要研究分析了基于光纤激光阵列的复合环形腔被动相干合成技术的路数扩展特性、抗相位扰动特性、偏振选择特性、脉冲合成特性以及光束拼接技术。详细报道了相关研究结果并总结分析了该技术方案的发展趋势。
激光器 相干合成 光纤放大器 被动锁相