高功率、低量子亏损同带抽运掺镱光纤放大器

开展了基于同带抽运的高功率、低量子亏损的掺镱光纤放大器实验研究. 搭建了一台输出功率为21 W的1018 nm短波 长掺镱光纤激光器, 并利用其对双包层掺镱光纤进行同带抽运, 获得18.6 W的1080 nm波段激光输出, 光-光转换效率高达90.86%. 关键词： 光纤放大器 同带抽运 双包层光纤 转换效率     

国产25/400μm掺镱双包层光纤实现2.2kW窄线宽单模激光输出

基于自主研制的均匀掺杂低热光系数25/400μm掺镱双包层光纤,开展了全光纤高功率窄线宽光纤激光放大实验。激光系统实现了中心波长为1060.3 nm、线宽为25 GHz、最高功率为2.2 kW的单模激光输出,其斜率效率达78%,光束质量因子M~2≈1.2,其功率是目前报道的基于国产25/400μm掺镱双包层光纤窄线宽放大器单模激光输出的最高功率。     

空气包层大模场面积掺镱光子晶体光纤研究

采用改进的化学气相沉积法和气相液相混合掺杂技术制备大芯径掺镱石英光纤预制棒, 以此作为有源纤芯制备了纤芯直径约90 μm的掺镱双包层光子晶体光纤, 纤芯组分为镱铝磷共掺.双包层光子晶体光纤的模场面积约1330 μm², 纤芯数值孔径0.065,包层数值孔径0.5.首次实现了国产掺镱光子晶体光纤的高功率高效率激光输出, 1 m长的光子晶体光纤激光器实现102 W 激光输出,斜率效率76%.     

915nm泵浦混合掺铒/铒镱共掺双包层光纤放大器

研究了一种混合掺铒/铒镱共掺光纤放大器,用掺铒光纤放大器作为输入信号的预放大器,用铒镱共掺双包层光纤放大器作为主放大器。掺铒光纤放大器采用20m长掺铒光纤作为增益介质,采用最大输出功率318mW的单模半导体激光器二极管作为泵浦源,预放大器获得的最大输出功率是113mW。铒镱共掺光纤放大器采用14m长铒镱共掺双包层光纤作为增益介质,采用2个915nm多模半导体激光二极管作为泵浦源,在输入信号功率为10mW、信号波长1555nm时,混合光纤放大器获得了最大输出功率为32.04dBm,即1.6W,与此相应的混合光纤放大器的光-光转换效率为18.5%。     

高效率可调谐掺镱双包层光纤激光器研究

研究了一种高效率可调谐掺镱双包层光纤激光器，在抽运半导体激光为915nm、功率为1W的条件下，掺镱双包层光纤激光器的最大输出功率为440mW，输出斜效率约为80％。输出光束的M^2因子为：x方向1．06，y方向1．04。用一光栅作为输出耦合，输出波长可在1070nm-1150nm的范围内调谐。     

基于M型掺镱光纤的近单模2 kW光纤放大器

模式不稳定效应和非线性效应已经成为高功率光纤激光器中限制输出功率和光束质量进一步提升的主要障碍.采用改进的化学气相沉积工艺结合溶液掺杂技术制备25/400μm的M型掺镱双包层光纤,纤芯和中间凹陷区域的数值孔径分别为0.054和0.025.基于该光纤搭建976 nm双向泵浦全光纤结构放大器.在泵浦光功率为3283 W时,获得2285 W中心波长为1080 nm的激光输出,3 dB线宽为3.01 nm,测量的光束质量因子为1.42,且未出现受激拉曼散射现象.这是目前基于M型掺镱光纤实现的最高输出功率,通过优化光纤结构参数实现功率进一步提升是有希望的.     

Yb/P/Al共掺双包层光纤的制备与激光性能

采用改进化学汽相沉积结合溶液掺杂法制备了Yb/P/Al共掺的石英光纤预制棒,通过光纤芯层的组份和制备工艺的优化,实现了Yb3+的高浓度掺杂和均匀掺杂.预制棒芯层Yb2O3掺杂浓度达到～4wt.％,Yb3+在1 080 nm处荧光寿命为1 780μs.成功拉制出内包层截面形状为八边形的双包层光纤,纤芯直径为7.5 μm,包层吸收系数达到～5 dB/m@976 nm.利用拉制的掺镱双包层光纤开展了全光纤结构的掺镱光纤激光器性能测试实验,实现了5.15W的激光输出,斜率效率达到76％.     

大功率多波长可转换双包层光纤激光器

在多模掺镱双包层光纤上,利用相位掩模法直接写制Bragg光栅作为激光器后腔镜,得到多波长激光输出.在室温下,通过调节偏振控制器可以得到稳定的单波长及多波长的激光输出,输出波长范围在1 056～1 061 nm,线宽均小于0.02 nm.在25 W的976 nm激光泵浦下,激光器得到功率为6 W的多波长输出.     

基于光纤光栅谐振腔的掺镱全光纤激光器设计(英文)

采用数值分析方法分析了光纤长度、后腔镜反射率等因素对激光器输出阈值泵浦功率、输出功率的影响,为全光纤激光器的优化设计提供了理论基础.在设计过程中采用光纤光栅作为光纤激光器的反馈与选频腔镜,通过锥度光纤实现了泵浦模块与掺镱双包层光纤之间的低损耗连接以及高效率的泵浦激光功率传输,成功研制了具备稳定窄化线宽激光输出的掺镱全光纤激光器.实验得到了波长峰值在1 082 .50 nm,谱线宽度0 .113 nm,最大输出功率8 .5 W,泵浦阈值功率0 .8 W,斜率效率为70 .8 %的稳定激光输出.     

1μm全光纤MOPA结构激光器输出特性研究

主振荡功率放大（main oscillation power amplification, MOPA）结构由于其光束质量良好和参数可调的优点,已成为高功率光纤激光器的主流设计之一。为了改善高功率掺镱光纤激光器（ytterbium-doped fiber laser, YDFL）的输出性能,提高系统的光-光转换效率,文中报道了一台基于915 nm泵浦激光器和双包层掺镱光纤（ytterbium-doped fiber, YDF）的MOPA结构全光纤高功率激光器。该高功率光纤激光器由电调制激光二极管（laser diode, LD）泵浦的种子激光器和掺镱光纤放大器（ytterbium-doped fiber amplifier, YDFA）组成。连续光（continuous wave, CW）工作模式下,激光种子源经过YDFA后,实现了中心波长为1 069.96 nm的激光输出,最大平均输出功率可达945.9 W,MOPA激光器整机的斜率效率高达74.12%,具有良好的稳健性。该研究方案对研制高功率MOPA光纤激光器具有参考意义。     

全光纤超短脉冲掺Yb3+光纤环形激光器

讨论了自启动被动锁模掺Yb³⁺光纤环形激光器产生短脉冲的机理，并研制出全光纤结构超短脉冲掺Yb³⁺光纤环形激光器.采用两个976nm半导体激光器级联抽运作为抽运源，高掺杂浓度掺Yb³⁺光纤作为增益介质，利用光纤的非线性偏振旋转效应，得到自启动、十分稳定的ps量级锁模光脉冲.激光器锁模阈值功率260mW，输出功率25mW，锁模光脉冲中心波长1056nm，3dB带宽11.7nm，重复频率20MHz.与其他结构光纤激光器相比，这种全光纤结构具有更高的效率和更好的稳定性. 关键词： 环形光纤激光器 3+光纤')" href="#">高掺杂浓度掺Yb³⁺光纤 自启动 被动锁模     

利用光谱滤波器实现自启动的全光纤超短脉冲掺Yb3+光纤激光器

讨论了利用光谱滤波器实现自启动的被动锁模掺Yb³⁺光纤环形激光器的锁模机理,并研制出全光纤结构超短脉冲掺Yb³⁺光纤环形激光器.使用980 nm二极管激光器作为抽运源,高掺杂浓度掺Yb³⁺光纤作为增益介质.在净群速度色散为正的环形腔中加入光谱滤波器,抑制Yb³⁺离子在1030 nm强发射峰的同时,通过对啁啾脉冲的光谱滤波实现脉冲压缩.光谱滤波器与光纤非线性偏振旋转效应相结合,实现了激光器在1053 nm可自启动、十分稳定的锁模运转.激光器锁模阈值功率300 mW,平均斜率效率18.3%,最大输出功率53.07 mW,对应最大输出脉冲能量3.2 nJ.锁模光脉冲中心波长1053.6 nm,3 dB带宽10.84 nm,重复频率16.45 MHz.锁模脉冲宽度为皮秒量级,经腔外光栅对压缩至188 fs. 关键词： 3+光纤激光器')" href="#">掺Yb³⁺光纤激光器 自启动锁模 全光纤     

Numerical investigation of gain characteristics of Er3+/Yb3+ co-doped fiber amplifiers

In this work, a model for analyzing the gain characteristics of heavily Er³⁺/Yb³⁺ co-doped compact fiber amplifier is presented. Four-level rate equations and finite-difference beam propagation method are applied to simulate the optical field evolution along the active fiber. Based on this model, the influences of ion concentration, fiber length and pump power on the gain characteristics of Er³⁺/Yb³⁺ co-doped phosphate glass fiber amplifiers are theoretically investigated. Numerical results show that for a fiber length of 3.6 cm the internal gain can reach 27.2 dB with N _Er = 2.6 × 10²⁶ ions/m³ and N _Yb = 1.2 × 10²⁷ ions/m³ when pumped with 224 mW at 980 nm. The gain per centimeter is 7.56 dB/cm. The results can provide useful information to optimize the gain performance of these compact fiber amplifiers.     

高浓度镱铒共掺磷酸盐光纤放大器增益特性

在忽略高能级的自发辐射和光纤损耗的情况下，利用速率方程和传输方程理论研究了高浓度Er³⁺/Yb³⁺共掺磷酸盐玻璃光纤放大器的增益特性，讨论了Er³⁺浓度、Yb³⁺浓度、抽运光功率、信号光功率、光纤长度对放大器增益的影响，并与单掺铒光纤放大器进行了比较.由于Yb³⁺的敏化作用降低了铒离子的团簇效应，减少了离子间相互作用，共掺光纤的增益和效率明显高于单掺光纤.数值计算表明，3.2cm长Er³⁺/Yb³⁺共掺光纤在980nm的20dBm(100mW)抽运功率下，1532nm处的增益可达10dB. 关键词： 镱铒共掺光纤放大器 速率方程 传输方程 高浓度     

Wide band gain flattening Yb-doped fiber amplifier

The gain flattening of Yb³⁺-doped fiber amplifier of 1053 nm band has been realized in experiment using three cascade 1 × 2 fused tapered fiber coupler. The gain flattening band is about 20 nm with less than 1 dB power fluctuation around 1053 nm, which is agree with our numerical stimulation results very well.     

Threshold characteristics of linear cavity Yb-doped double-clad fiber laser

The threshold characteristics of linear cavity Yb³⁺-doped double-clad fiber laser have been studied theoretically and experimentally. By solving rate equations, the expression for threshold pump power is obtained. The effects of fiber length, mirror reflectivity, pump wavelength, laser wavelength and Yb³⁺ concentration on threshold pump power are discussed. Then, the Yb³⁺-doped double-clad fiber laser with linear cavity is developed. By using various output couplers, threshold pump power has been measured. The experimental results are in accord with theory.     

Wavelength tunable linear cavity cladding pump Er<Superscript>3+</Superscript>/Yb<Superscript>3+</Superscript>co-doped fiber laser operating in L-band

We have demonstrated a novel tunable linear cavity Er³⁺/Yb³⁺ co-doped fiber laser, which utilizes amplified spontaneous emission as a secondary pump source so that it can operate in L-band. The tuning wavelength range can be up to 34 nm, from 1588.6 to 1622.6 nm, and the output power excursion of the laser at different wavelengths can be less than 0.4 dB by using a two sections of high-birefringence fiber loop mirror as the wavelength filter. The high output power of 200 mW is realized by using the cladding-pump.     

高效率掺Tm~(3+)双包层光纤及光纤激光器的研制

掺Tm3+光纤激光器有着广泛的应用前景,而掺Tm3+光纤是其核心与关键.本文采用改进的化学汽相沉积(MCVD)工艺和气相液相复合掺杂技术,在MCVD机车上实现了掺Tm3+石英光纤预制棒的制备,并制备了掺Tm3+石英双包层光纤(芯包比为10/125).利用上述光纤搭建直腔型全光纤激光器,在波长为793nm的LD抽运下,获得激光光谱中心波长为2002 nm,最大的激光输出功率30.7 W,光纤斜率效率为59.32%.     

Novel shooting method with simple control strategy for fiber lasers

A novel shooting method with excellent simple control strategy is developed for solving the failure to convergence of the traditional shooting methods themselves in fiber lasers model. Compared with the published literature, the novel shooting method provides a clear physical understanding method for getting the threshold pump power and the exact results with given random functions in Yb³⁺-doped fiber lasers and Er³⁺-doped fiber lasers. Then, the results in Er³⁺-doped fiber lasers and Yb³⁺-doped fiber lasers demonstrate that the solutions using the novel shooting method has high accuracy of 10⁻⁸ W with several iteration steps, which have extended the applicable range of the end-pumped power even lower than 1 mW pump power. Furthermore, compared with 1480 nm pump for the threshold and slope efficiencies of the Er³⁺-doped fiber lasers, 978 nm fiber lasers can extend wider scope of application and be pump source in the coming future. Finally, the lower threshold and higher slope efficiency at 975 nm than those of 910 nm pump in Yb³⁺-doped fiber lasers, 975 nm pump laser provides for broad band excellent cladding pump source.     

Multi-Wavelength-Switchable Double Clad Yb3+-Doped Fiber Laser Based on Reflectivity Control of Fiber Bragg Gratings by Induced Bend Loss

We propose and demonstrate an all-fiber multi-wavelength switchable double-clad Yb³⁺-doped fiber laser based on the reflectivity cavity control by induced bend loss. The wavelength switching is realized by a variable reflecting mirror that employs a cascaded array of three high reflection (>99%) fiber Bragg gratings at 1064, 1080 and 1096 nm, with a bending controller inserted between each grating. The order of the Bragg gratings is decided according to the gain profile of the Yb³⁺-doped fiber and the induced bending loss allows us to select the Bragg-wavelength laser operation. The laser is capable of switching continuously from one wavelength to another, and slope efficiencies over 50% are obtained at each wavelength.