300 W侧面分布式抽运掺Yb全光纤放大器

采用角度磨抛的方式, 在纤芯/包层为20/400 μm双包层掺Yb光纤上制作了侧面抽运耦合器. 该耦合器对975 nm的半导体二极管抽运光的耦合效率最高可达97%, 对1080 nm信号光的泄漏比小于2%. 分析了侧面抽运耦合器的性能以及多个侧面抽运耦合器的级联分布对抽运耦合效率的影响; 同时, 在前向抽运和双向抽运方式下, 分析了级联耦合器的分布及信号光泄漏比对激光器整体效率的影响, 并进行了数值模拟. 采用自行研制的侧面抽运耦合器, 搭建了侧面耦合分布式抽运、掺Yb双包层全光纤主振荡功率放大器, 获得了波长为1080 nm、功率为303 W 的基模激光输出. 进一步增加抽运点个数, 提高抽运功率, 可获得更高的输出功率.     

侧面抽运掺Yb3+双包层光纤激光器的理论研究

建立了侧面抽运掺Yb3+双包层光纤激光器的数值模型,推导出激光分布的近似解析式,并进行了数值模拟,得到了光纤内抽运光和激光功率的分布特性,以及激光输出功率随抽运光注入位置,光纤长度以及端镜反射率的变化关系.结果表明,抽运光注入位置对激光分布和激光输出功率有较大的影响.     

4.9 W掺Yb3+双包层光纤激光器及其输出特性研究

报道了输出波长为1110nm、最大输出功率4．9W、光束质量接近衍射极限的连续波掺Yb^3 双包层光纤激光器。实验采用矩形内包层的石英掺Yb^3 双包层光纤，抽运源为中心波长在910nm附近的半导体激光器，当抽运光功率为12W时，获得了4．9W的激光输出，斜率效率为43．6％。     

利用光纤光栅的高功率掺镱光纤激光器

报道了利用一对光纤光栅作为双包层Yb^3 掺杂光纤激光器的谐振腔，激光二极管光纤模块(LD)进行了抽运，并采用锥形光纤实现了全光纤化结构，获得了高功率双包层光纤激光器。光纤光栅通常是用融接技术实现与双包层光纤的一体化连接的，采用的双包层光纤为内包层为梅花瓣形结构的掺Yb^3 离子的石英光纤，采用的抽运源为中心波长为970nm的半导体激光光纤输出模块，在抽运源电流达到2．4A时，获得了10．8W的光纤激光器单横模输出，输出波长1100．5nm，峰值半峰全宽(FWHM)为0．54nm，激光器斜效率为59％。     

双包层光纤激光器微棱镜反射式侧面耦合的新技术

提出了一种双包层光纤激光器侧面耦合技术--微棱镜反射式侧面耦合技术,能高效且方便地将半导体激光器,特别是高功率半导体激光器阵列和叠层的抽运光耦合进双包层光纤中.该技术具有结构简单、加工难度小,抽运效率高、对光纤本身无损伤等特点,更重要的是该技术非常适合半导体激光器列阵的多点抽运.详细阐述了微棱镜反射式耦合技术的基本原理和具体使用方法,理论计算所得耦合效率超过90%,并进行了初步的实验研究,得到了超过50%的耦合效率.通过分析,对光源和棱镜具体尺寸参数提出了具体要求,并指出了其应用范围.     

高功率双包层光纤激光器抽运技术的方案分析

介绍了高功率光纤放大器双包层光纤的结构特点和双包层抽运的基本原理,在此基础上对高功率双包层光纤激光器的抽运关键技术作了分析,详细讨论了端面抽运技术、熔锥侧面抽运技术、内嵌反射镜抽运技术、角度抛光侧面抽运技术和V形槽侧面抽运技术等多种侧面抽运技术的结构及系统性能参数,并对各种侧面抽运技术的优缺点作了比较分析.研究结果表明,侧面抽运比端面抽运更有利于获得高功率激光输出,而在侧面抽运技术中则以V形槽侧面抽运技术为佳.     

大功率掺Yb双包层光纤宽带超荧光光源

利用波长为976nm的半导体激光器抽运掺Yb双包层光纤,制成了大功率光纤宽带超荧光光源,最大超荧光输出功率为54.11mW;此时斜率效率为69．35％,中心波长为1082nm,3dB带宽为17．2nm。     

单模与多模光纤耦合器的光束合波

现有的光纤耦合器在作为分波器使用时具有较低的插入损耗,在作为合波器时插入损耗较大,为实现低损耗合波目的,提出一种由单模与多模光纤共同构成的混合型光纤耦合器。利用耦合波方程理论分析其工作原理,计算机模拟其耦合过程。采用熔锥法制作工艺,完成单模与多模光纤耦合器的制作,实验结果与理论模拟相吻合;该器件单模到多模光纤的耦合效率、多模到多模光纤的耦合效率均在90％以上,实现了两路光束的功率合波。作为低插入损耗合波器件可广泛应用于光通信以及双包层光纤激光器抽运光的注入。     

光纤光栅选频掺Yb3+双包层光纤激光器

利用相位掩模法，在D形内包层掺Yb3+双包层光纤一端直接写制出Bragg光栅，用作双包层光纤激光器的输出腔镜.试验得到了线宽为0.196nm，波长为1058.2nm，最高输出功率为570mW的稳定激光输出，解决了激光器中模式竞争造成的输出不稳定现象.从速率方程出发，对激光器的输出功率与抽运功率、光栅反射率的关系以及最佳光纤长度进行了理论分析，结果与实验符合很好. 关键词： 双包层光纤光栅 掺Yb3＋双包层光纤激光器 相位掩模 速率方程     

双端抽运的掺Yb^3＋双包层光纤激光器中合作发光效应

合作发光效应、热效应以及非线性效应限制了单根掺Yb^3＋光纤激光器输出功率的进一步提高。根据能级间的吸收与辐射，分析了掺Yb^3＋双包层光纤中的合作发光效应，分析表明，随着Yb^3＋的掺杂浓度的增大，光纤中合作发光增强，抽运光越强，合作发光也越强。实验研究了输出功率61．6W，斜率效率为55％的双端抽运的掺Yb^3＋双包层光纤激光器的合作发光效应，研究表明，随着抽运光功率的增大，合作发光强度增强，掺杂浓度越大，光纤中合作发光效应也越强。这一结果有利于进一步提高掺Yb^3＋光纤激光器的效率。     

Multi-coupler side-pumped Yb-doped double-clad fiber laser

The side-coupler of angle polished method, using angle-polished multimode fiber and optical adhesive, is used to efficiently pump an Yb-doped double-clad fiber laser. The maximum coupling efficiency of 78.6% is achieved by the side-coupler for a multimode fiber with a circular core of 200 μm and a double-clad fiber with a 350/400 μm D-shaped inner cladding. While laser diodes (LDs) with three side-couplers are simultaneously used as pump sources, maximum output power of 1.38 W and slope efficiency of 48.9% are demonstrated in the fiber laser system.     

包层泵浦掺镱光纤激光器的理论和实验研究

从包层泵浦光纤激光器的速率方程理论出发,推导出了稳态下包层泵浦光纤激光器的输出功率,斜率效率和阈值功率的解析表达式,进行了数值模拟,对模拟结果进行了简单分析。并进行了实验研究,实验采用中心波长为975nm的激光二级管单端泵浦内包层形状为D型的包层光纤,利用二相色镜和光纤端面反馈构成谐振腔,采用了两套不同的准直耦合系统,得到的最高输出功率为24W,总的光-光转换效率为53.5%。     

Theoretical and experimental investigation of thermal effects in a high power Yb-doped double-clad fiber laser

In this paper, based on the thermal conduction equations and the steady-state rate equations, a theoretical and numerical analysis of thermal effects is investigated for a single end pumped Yb-doped double-clad fiber laser (YDDC). The distributions of signal power and temperature for different pump powers and fiber parameters are compared. According to the results, the parameters of the optical-cavity have been optimized and an effective method has been adopted to reduce the thermal effects in an experimental investigation. As a result, an output power of 621 W has been obtained with a slope efficiency of 78%.     

Generation of radially polarized mode in Yb fiber laser by using a dual conical prism

For the first time to our knowledge, a radially polarized beam is generated in an Yb-doped multimode double-clad fiber laser by using an intracavity dual conical prism. Up to 6.2 mW of output power is obtained from a 2 m long gain fiber with 7.4% slope efficiency. This research opens a new window to obtaining a radially polarized beam directly from an active fiber.     

Output Characteristics of High-Power Continuous Wave Raman Fiber Laser at 1239 nm Using Phosphosilicate Fiber

A high-power singlemode Raman fiber laser (RFL) with maximum output power of 4.11 W and maximum power conversion efficiency of 47.40% at 1239 nm is realized using continuous wave 8.4 W Yb-doped double-clad fiber laser as a pump, 700 m phosphosilicate fiber, and a Raman cavity formed by a pair of fiber Bragg grating mirrors at 1239 nm. The output characteristics of the RFL at 1239 nm for different fiber lengths and output mirror reflectance are reported. Theoretical simulation is done to numerically optimize for fiber length and output coupler reflectivity to obtain maximum first Stokes power.     

ps级脉冲光纤放大器和压缩器

 对掺镱双包层脉冲光纤放大器进行实验研究。当用入纤功率为1.9 W的半导体激光器激光泵浦0.5 m长的双包层掺镱光纤时,把平均功率为7 mW、重复频率25.4 MHz的激光放大到505 mW,相应的单脉冲能量为19.8 nJ,经过光栅对压缩后,得到2.7 ps的脉冲激光。     

Experimental demonstration of novel end-pumping method for double-clad fiber devices

We present experimental demonstration of an end-pumping scheme based on splicing the multimode pump and single-mode signal fibers directly to a double-clad fiber with a tailored cross section. The method is used to pump a double-clad, erbium- and ytterbium-doped, fiber ring laser. The efficiency of the end-pumping method is tested by determining the slope efficiencies of the fiber ring laser and the fiber laser in a Fabry-Perot configuration. Comparable slope efficiencies are found when both laser configurations have similar output coupler ratios. The developed pumping scheme and double-clad fiber can find applications in cost-effective power fiber amplifiers and lasers.     

10-W cladding-pumped fiber laser with single transverse mode output

A Yb-doped double-clad fiber laser is demonstrated with a measured power output of 10.6 W and a fundamental spatial mode. The optical-to-optical conversion efficiency is 44% and the slope efficiency is 86% closed to quantum efficiency of optical conversion. In our laser system, a D-shape (340 μm/400 μm) inner cladding Yb-doped fiber is used as the gain material within the Fabry-Perot cavity. Multimode diode pump radiation is injected into the cladding through an end facet of the composite fiber.     

包层泵浦的铒镱共掺光纤激光高效产生的实验研究

利用尾纤输出的977nm高亮度多模半导体激光器包层泵浦铒镱共掺双包层光纤,采用非球面透镜组耦合方式,使泵浦耦合效率达66%以上,并在法布里-珀罗激光振荡腔结构中实现了高效的连续激光产生,双包层光纤长度为2m,在泵浦入纤功率为1.36W时,输出连续功率最大394mW,斜率效率达35%,激光输出波长1.565μm.