1 中国科学院上海光学精密机械研究所高功率光纤激光技术实验室，上海 201800
2 中国科学院大学材料科学与光电技术学院，北京 100049
3 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
调Q技术是掺铥光纤激光器获得纳秒脉冲激光输出的主要方式。本文首先介绍主动调Q、被动调Q和增益调制这三种调Q技术在掺铥光纤振荡器中的应用现状，对比和分析三种技术的优点与不足。其次，介绍窄脉宽、高平均功率、大脉冲能量纳秒掺铥光纤放大器的现有典型研究结果和面临的技术瓶颈，并从热管理、非线性效应抑制、放大自发辐射抑制三个方面进行了优化措施分析。最后，对纳秒掺铥光纤振荡器和放大器的技术发展趋势进行展望。
激光器 纳秒掺铥光纤激光器 主动调Q 被动调Q 增益调制 激光与光电子学进展
2023, 60(9): 0900003
杭州电子科技大学通信工程学院，浙江 杭州 310018
设计了一种基于Nd∶GdVO4晶体的增益开关型正交偏振双波长同步脉冲激光器。建立了对应的速率方程数学模型，分析了增益开关型Nd∶GdVO4双波长同步脉冲激光器中的几何损耗对双波长脉冲时域特性的影响。搭建了基于布儒斯特偏振片的Y型腔结构的双波长脉冲激光器进行实验验证，通过调制抽运源电流实现了增益开关。实验结果表明，通过调节输出镜的倾斜角度，可实现双波长脉冲的同步输出。最后，当泵浦功率为6 W时，实验输出了脉冲重复频率为30.7~100.0 kHz可调、最高平均输出功率分别为215 mW和176 mW的正交偏振双波长［1063 nm（π偏振）和1065 nm（σ偏振）］同步脉冲。实验与理论结果吻合较好。
激光器 激光技术 增益开关 双波长激光器 时间特性
Author Affiliations
Abstract
1 State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an, China
2 Center for Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
A 1.7 μm gain-switched thulium-doped all-fiber laser with a master oscillator power amplifier (MOPA) configuration, utilizing a bandpass fiber filter and a 1550 nm erbium/ytterbium-codoped fiber MOPA, is demonstrated. The influences of pump pulse parameters (repetition rate and pulse duration) and laser cavity structures (ring and linear) on the laser performances were experimentally investigated. To the best of our knowledge, the power quenching and drop were observed in the 1.7 μm gain-switched thulium-doped fiber lasers for the first time, resulting from the mode-locked-resembling operation and nonlinear effects. Moreover, the fiber ring-cavity laser was more stable than the linear-cavity laser in the time domain and power. Finally, a laser with a maximum average power of 1.687 W, a slope efficiency of 19.7%, a single-pulse energy of 16.87 μJ, a pulse width of 425 ns, a repetition rate of 100 kHz and a peak power of 39.69 W was obtained.
1.7 μm gain-switching fiber laser power roll-off thulium doping High Power Laser Science and Engineering
2022, 10(6): 06000e40
1 电子科技大学基础与前沿研究院, 四川 成都 610054
2 西南技术物理研究所, 四川 成都 610041
量子通信是当前量子信息领域的研究前沿和热点。增益开关半导体激光产生技术是一种实现脉冲激光产生的成熟方法,将其与注入锁定技术结合,可以满足量子通信应用对激光脉冲的需求。系统地介绍了增益开关半导体激光器的工作原理和注入锁定方案,以及其在量子密钥分发、量子随机数产生等方面的应用现状,着重从物理原理、实验方案和最新研究进展等方面进行阐述,并对其下一步的发展进行简要展望。
对增益调制掺铥光纤激光器展开了系统性探究,基于速率方程与传输方程构建了增益调制掺铥光纤激光振荡器和放大器的数值模型,并通过时域有限差分法进行求解,从理论和实验上探究了不同的泵浦光及激光器结构参数下输出的2 μm激光特性。通过数值仿真和实验优化,获得了高转换效率、窄线宽、单一偏振的2 μm波段纳秒激光输出。种子源振荡器获得了最高功率为796 mW、脉宽为67.9 ns、斜效率为54.4%的脉冲激光;在一级放大器后得到了最高功率为9.13 W、脉宽为50.5 ns的2 μm脉冲激光。数值仿真模型的模拟结果与实验结果较好地吻合,该模型能够为该类型激光器的实验研究和工程设计提供参考。
激光器 掺铥光纤激光器 2 μm激光; 增益调制 数值仿真 激光与光电子学进展
2020, 57(19): 191404
Author Affiliations
Abstract
Department of Electronic Engineering, Xiamen University, Xiamen 361005, China
Mid-infrared (MIR) fiber pulsed lasers are of tremendous application interest in eye-safe LIDAR, spectroscopy, chemical detection and medicine. So far, these MIR lasers largely required bulk optical elements, complex free-space light alignment and large footprint, precluding compact all-fiber structure. Here, we proposed and demonstrated an all-fiberized structured gain-switched Ho3+-doped ZBLAN fiber laser operating around 2.9 μm. A home-made 1146 nm Raman fiber pulsed laser was utilized to pump highly concentrated single-cladding Ho3+-doped ZBLAN fiber with different lengths of 2 m or 0.25 m. A home-made MIR fiber mirror and a perpendicular-polished ZBLAN fiber end construct the all-fiberized MIR cavity. Stable gain-switched multiple states with a sub-pulse number tuned from 1 to 8 were observed. The effects of gain fiber length, pump power, pump repetition rate and output coupling ratio on performance of gain-switched pulses were further investigated in detail. The shortest pulse duration of 283 ns was attained with 10 kHz repetition rate. The pulsed laser, centered at 2.92 μm, had a maximum average output power of 54.2 mW and a slope efficiency of 10.12%. It is, to the best of our knowledge, the first time to demonstrate a mid-infrared gain-switched Ho3+:ZBLAN fiber laser with compact all-fiber structure.
fiber laser mid-infrared gain-switching Opto-Electronic Advances
2020, 3(5): 05190032
1 西南大学物理科学与技术学院, 重庆 400715
2 西南大学电子信息工程学院, 重庆 400715
提出了基于正交光注入增益开关850 nm垂直腔面发射激光器(850 nm-VCSEL)获取梳距可调双路宽带光学频率梳(OFC)的方案,通过数值仿真研究了系统参量对OFC性能的影响。在该方案中,首先采用大信号电流调制850 nm-VCSEL使其呈增益开关状态,此时Y偏振分量激射并呈周期脉冲状态,而X偏振分量被抑制,可以获得一路偏振沿Y方向的OFC(Y-OFC);进一步引入偏振方向沿X方向的注入光(即正交光注入),在合适的注入参数条件下,增益开关850 nm-VCSEL中的X偏振分量被激射并呈周期脉冲动力学状态,且输出的X偏振分量具有与Y偏振分量强度相当的光谱分布,从而可以获得两路正交的OFC。数值仿真的结果表明:受到调制频率fm=4.2 GHz、调制深度m=0.75的大信号电流调制的850 nm-VCSEL,在频率失谐Δv=10.0 GHz的正交光注入下,通过选取合适的注入光场振幅Einj可使激光器输出带宽(功率变化在10 dB范围内)超过105.0 GHz的双路宽带OFC。借助于正交光注入下增益开关850 nm-VCSEL输出的X偏振分量和Y偏振分量的光谱分布,确定了获得双路OFC所需的Einj和Δv的范围。最后,通过分析其他调制频率下所获取的OFC性能,论证了该方案产生双路宽带OFC梳距的可调谐性。
光通信 850 nm垂直腔面发射激光器(850 nm-VCSEL) 增益开关 正交光注入 光学频率梳(OFC) 梳距
Author Affiliations
Abstract
1 Key Laboratory of Photonic Control Technology (Tsinghua University), Ministry of Education, Beijing 100084, China
2 State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
3 School of Electronic and Information Engineering, Harbin Institute of Technology, Shenzhen 518055, China
4 National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001, China
The generation of mid-infrared pulsed lasers was achieved in a Ho3+:YAG laser pumped gain-switched Cr2+:CdSe laser system with the shortest pulse duration of 4.15 ns. With a pump pulse duration of 50 ns and pump power of 2.7 W, the gain-switched Cr2+:CdSe laser achieved over 10 times pulse narrowing, obtaining the maximum peak power of 5.7 kW. The optical-to-optical conversion efficiency was 3.7%, which could be further improved with better crystal surface polishing quality. The laser central wavelength was measured to be 2.65 μm with a bandwidth (FWHM) of 50 nm. In addition, the parameter optimization for suppressing the pulse tail was discussed, while the long cavity and high output transmissivity contributed to obtaining the single-peak pulses.
Cr2+:CdSe laser gain-switching pulse narrowing mid-infrared Chinese Optics Letters
2020, 18(3): 031403
1 深圳大学电子科学与技术学院深圳市激光工程重点实验室, 广东 深圳 518060
2 深圳大学光电工程学院深圳市激光工程重点实验室, 广东 深圳 518060
采用铒镱共掺光纤, 实现了一种双波长1.0 μm 调Q和1.5 μm增益开关脉冲光纤激光器。实验装置是一个双环腔结构, 两环的公共端共用一段铒镱共掺光纤。1.0 μm调Q脉冲通过未抽运铒镱共掺光纤的可饱和吸收效应产生。而铒镱共掺光纤对1.0 μm调Q脉冲的再吸收会周期性调制铒离子的反转粒子数, 从而产生重复频率相等的1.5 μm增益开关脉冲。随着抽运功率的增加, 这两种脉冲的重复频率从5.4 kHz增加到11.7 kHz。1.5 μm脉冲相对1.0 μm脉冲有一定的延迟, 并且延迟时间随着抽运功率的增大而不断减小。在最大抽运功率处, 1.0 μm脉冲宽度、单脉冲能量和最大平均输出功率分别是5.3 μs、402.6 nJ 和 4.7 mW, 而对于1.5 μm脉冲, 分别是4.6 μs、 374.4 nJ 和 4.4 mW。
激光器 双波长脉冲光纤激光器 调Q 增益开关 铒镱共掺光纤
1 电子科技大学光电信息学院, 四川 成都 610054
2 保密通信重点实验室, 四川 成都 610041
近30年来，量子信息科技是令人激动的研究领域之一。其中，量子保密通信技术，已逐渐开始从实验研究迈向工程应用，有望率先实现商用化发展。面向量子保密通信系统的全面普及和推广，基于半导体激光器的增益开关效应和商品电子学芯片，设计和实现了皮秒脉冲激光器模块。其特点包括：工作波长位于光纤量子信道的低损窗口，即1.5 μm波段；输出光频的波动小于20 MHz；光脉冲的时域宽度为10个皮秒量级；输出光脉冲间不具有确定的相位关系。进一步地，结合“弱相干”单光子源在量子保密通信技术中的应用，对上述特点进行检验和讨论。
量子光学 量子保密通信 半导体激光器 脉冲激光器 增益开关
