Demonstration of multi-Watt all-fiber superfluorescent source operating near 980 nm

The superfluorescent Yb-doped fiber source operating near 980 nm is studied. The design requirement is theoretically discussed aiming to suppress the amplified spontaneous emission around 1030 nm in the 980-nm superfluorescent fiber source. Based on the theoretical study, a multi-Watt, all-fiber, bi-directional, pumped, superfluorescent source operating near 980 nm is designed and experimentally demonstrated for the first time, to the best of our knowledge. The recorded 8.38-W combined output power is obtained with a 3-dB bandwidth about 3.5 nm. The power scaling of the 980-nm superfluorescent fiber source is limited by the parasitic laser oscillation.     

频率漂移对耦合激光器阵列锁相状态的影响

耦合激光器阵列可以通过激光器之间的倏逝波耦合实现相位锁定,是有望实现光束相干合成的方案之一。为了探究该阵列锁相状态的稳定性,分析了频率漂移对两路激光器阵列相位锁定状态的影响。通过对耦合激光器阵列动力学方程的数值研究发现,频率漂移将破坏激光器阵列的锁相状态,并引入相位噪声,导致输出远场光强分布不稳定; 研究还发现：倏逝波耦合能够对频率漂移的影响起到一定的抑制作用,但这种抑制只在频率漂移较弱时才有效,因此,如果将该阵列用于光束合成,加入相应的抗干扰措施还是很必要的。数值分析的结果还表明：频率漂移的低频成分对于阵列相位锁定状态的影响更为剧烈,因此,抗干扰措施应主要针对低频干扰来进行。     

自主研发的976nm波段全光纤激光器实现了100W量级功率输出

正976nm波段掺镱光纤激光器可作为高功率掺镱/铒光纤激光器的高亮度泵源,在蓝光和紫外光源等领域也有良好的应用前景,因而备受关注。不过,由于其三能级跃迁特性导致的泵浦阈值高、放大自发辐射强等问题,该激光器的功率提升面临巨大挑战。现阶段,国际上976nm波段光纤激光器的输出功率达到100 W量级,而国内976nm波段光纤激光器的输出功率仅为20 W量级。国防科技大学针对影响该激光器功率提升的     

Research on effects of active fiber length and dopant concentration on 976-nm Yb-doped fiber amplifiers

In this letter, the theoretical model and rate equations of Ytterbium-doped double-clad fiber amplifiers are introduced. The output performance of fiber amplifiers is analyzed through numerical simulations considering three main factors： active fiber length, pump power, and dopant concentration. It is found that the output signal power experiences a stable growth and then decreases rapidly as the active fiber length becomes longer. It is also revealed that the dopant concentration shows similar effects as active fiber length on the output signal power of fiber amplifiers.     

光的相干和偏振的相关研究进展

相干和偏振是统计光学体系中紧密联系的两个方面,对激光的传输性质有重要的影响。介绍了相干偏振的基本理论,尤其是以交叉谱密度矩阵为基础的相干和偏振的统一理论。分析介绍了当前该领域的研究热点:偏振特性的传输变化、部分相干光散射理论、谱交叉偏振度(SDCP)和三维随机电磁光束。对相干偏振理论的相关问题进行了总结和展望。