Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 School of Information and Communications, National University of Defense Technology, Wuhan 430035, China
3 Nanhu Laser Laboratory, National University of Defense Technology, Changsha 410073, China
4 Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha 410073, China
High-power ultrafast laser amplification based on a non-polarization maintaining fiber chirped pulse amplifier is demonstrated. The active polarization control technology based on the root-mean-square propagation (RMS-prop) algorithm is employed to guarantee a linearly polarized output from the system. A maximum output power of 402.3 W at a repetition rate of 80 MHz is realized with a polarization extinction ratio (PER) of > 11.4 dB. In addition, the reliable operation of the system is verified by examining the stability and noise properties of the amplified laser. The M2 factor of the laser beam at the highest output power is measured to be less than 1.15, indicating a diffraction-limited beam quality. Finally, the amplified laser pulse is temporally compressed to 755 fs with a highest average power of 273.8 W. This is the first time, to the best of our knowledge, that the active polarization control technology was introduced into the high-power ultrafast fiber amplifier.
active polarization control root-mean-square propagation algorithm linearly polarized laser chirped pulse amplification femtosecond laser fiber laser Chinese Optics Letters
2024, 22(4): 041403
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学南湖之光实验室,湖南 长沙 410073
3 国防科技大学高能激光技术湖南省重点实验室,湖南 长沙 410073
强激光与粒子束
2024, 36(1): 011001
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学南湖之光实验室,湖南 长沙 410073
光纤光栅(FBG)在高功率光纤振荡器中发挥着重要作用,既可以作为谐振腔腔镜,又可以抑制受激拉曼散射(SRS)效应。使用飞秒激光在芯径为30 μm的大模场双包层光纤(LMA-DCF)上刻写了波长为1080 nm的FBG对以及波长为1135 nm的啁啾倾斜光纤光栅(CTFBG),利用FBG对搭建了全光纤振荡器,并使用CTFBG抑制了SRS,实现了9 kW激光功率输出,斜率效率为83.4%。研究结果有利于推动高功率FBG的研制和高功率光纤振荡器的发展。
光纤光学 飞秒激光 光纤振荡器 高功率激光器 受激拉曼散射 光纤光栅
Author Affiliations
Abstract
1 College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
2 Nanhu Laser Laboratory, National University of Defense Technology, Changsha 410073, China
3 Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha 410073, China
The high-power mode-programmable orbital angular momentum (OAM) beam has attracted significant attention in a wide range of applications, such as long-distance optical communication, nonlinear frequency conversion, and beam shaping. Coherent beam combining (CBC) of an optical phased array (OPA) can offer a promising solution for both generating the high-power OAM beam and rapidly switching the OAM modes. However, achieving real-time phase noise locking and formation of desired phase structures in a high-power CBC system faces significant challenges. Here, an internal phase-sensing technique was utilized to generate the high-power OAM beam, which effectively mitigated thermal effects and eliminated the need for large optical devices. An OPA with six elements was employed for experimental demonstration. The first effective generation of over 1.5 kW mode-programmable OAM beam in a continuous-wave domain was presented. Moreover, the results demonstrated that the generated OAM beam could be modulated with multiple dimensions. The topological charge can be switched in real time from -1 to -2. Notably, this OAM beam emitter could function as an OAM beam copier by easily transforming a single OAM beam into an OAM beam array. More importantly, a comprehensive analysis was conducted on power scaling, mode switching speed, and expansion of OAM modes. Additionally, the system’s compact design enabled it to function as a packageable OAM beam emitter. Owing to the advantages of having high power and programmable modes with multiple dimension modulation in phase structures and intensity distribution, this work can pave the way for producing high-power structured light beams and advancing their applications.
orbital angular momentum optical vortex optical phased array coherent beam combining Chinese Optics Letters
2024, 22(2): 021402
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学南湖之光实验室,湖南 长沙 410073
3 国防科技大学高能激光技术湖南省重点实验室,湖南 长沙 410073
以19路、127路和919路激光相干阵列为模型,通过倾斜波前调控技术对阵列光场的子阵元施加倾斜相位控制,对倾斜可控阵列光场的大角度二维扫描特性进行了理论和实验研究。结果表明,所提出的方法可实现大视场范围内任意位置的单点扫描,同时得到能量分布均匀的二维连续扫描路径,实现特殊光场图案定制。此外,该方法具有扫描范围不受限制、扫描模式准连续以及衍射效率高等特点,在提升输出功率和扫描精度等方面具有优势。
激光光学 激光阵列 相干合成 倾斜调控 二维扫描 光场定制
1 天津职业技术师范大学 机械工程学院,天津 300222
2 天津职业技术师范大学 机械工程学院,天津 300222天津市高速切削与精密加工重点实验室,天津 300222
为了能够实现高精度的微纳米级转动,该文基于柔性铰链设计了一种单压电陶瓷驱动的纯转动微定位平台。平台采用圆周阵列式柔性梁实现运动导向与解耦,通过杠杆机构增大动平台转动行程。首先通过有限元仿真验证了圆周阵列式柔性梁对动平台轴心漂移的抑制作用,然后通过实验对其运动特征进行测试与分析。测试结果表明,该机构具有良好的回转精度,在x轴正方向轴心漂移量为0~0.23 μm,y轴负方向轴心漂移量为0~4.59 μm,旋转弧度可达916 μrad,旋转精度为0.53 μrad。轴心漂移补偿后整体误差最大为4.9%。
压电陶瓷 微转动平台 柔性铰链 轴漂 旋转弧度 piezoelectric ceramic micro-rotational platform flexible hinge axial drift rotation radian
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学南湖之光实验室,湖南 长沙 410073
中国激光
2023, 50(21): 2116002
王鹏 1,2,3奚小明 1,2,3孟祥明 1王小林 1,2,3,*[ ... ]陈金宝 1,2,3,**
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学南湖之光实验室,湖南 长沙 410073
3 国防科技大学高能激光技术湖南省重点实验室,湖南 长沙 410073
中国激光
2023, 50(21): 2116001
1 国防科技大学前沿交叉学科学院,湖南 长沙 410073
2 国防科技大学信息通信学院,湖北 武汉 430035
3 国防科技大学南湖之光实验室,湖南 长沙 410073
4 国防科技大学高能激光技术湖南省重点实验室,湖南 长沙 410073
中国激光
2023, 50(19): 1916001