基于DFB激光器的楔形截顶光纤微透镜耦合结构

为了解决分布式反馈激光器的光发射次模块耦合封装中存在最大耦合效率局限的问题, 采用楔形截顶光纤微透镜代替分立式透镜的直接耦合的方法, 得到斜面倾角0.6rad、耦合距离60μm、半宽度15μm的楔形截顶光纤端面模型。在此基础上与分立式和直接耦合进行对比, 讨论了纵向、横向和角度偏移误差。结果表明, 纵向耦合距离在-21.45μm~56.79μm, 角向耦合角度在-8.3°~8.5°, 耦合效率始终大于70%;结构整体容忍度较高, 耦合效率达84.40%。该研究可为下一代分布式反馈激光器的次发射模块耦合封装器件提供新的解决方案。     

33 W半导体激光器列阵光纤耦合模块

利用光纤柱透镜和光束转换装置压缩半导体激光器列阵（LDA）的发散角，然后通过聚焦透镜将激光束耦合入芯径为400μm的微球透镜光纤。LDA与光纤耦合输出后，实现33W的高出纤功率，最高耦合效率大于80％，光纤的数值孔径（NA）为0．22。     

激光器与单模光纤球透镜耦合的蒙特卡洛分析

为了研究半导体激光器与单模光纤在采用球透镜耦合方式的封装过程中不同耦合参量对耦合效率的影响,建立了半导体激光器与单模光纤通过球透镜耦合的光传输模型。基于ABCD矩阵和高斯光束与单模光纤耦合理论,计算了半导体激光器与单模光纤的球透镜耦合效率,以光功率下降0.5dB为评判标准,给出了在透镜半径为0.5mm时的各参量容忍度。采用蒙特卡洛分析方法,结合耦合效率计算模型,模拟仿真了各参量满足正态分布时的耦合效率分布状况。结果表明,能达到的最大耦合效率为0.616,最大概率耦合效率为0.585,参量区间缩小一半对耦合效率的提升较明显,但进一步缩小参量区间对耦合效率的提升不明显。此研究方法对激光器件封装过程中的对准单元精度选取与耦合效率预估具有指导意义。     

双包层掺杂光纤端面泵浦技术的研究

设计了一种基于准直聚焦透镜组的双包层掺杂光纤端面泵浦耦合系统,通过分析多模光纤耦合输出的泵浦光束参量经准直聚焦透镜光学系统后的变换特性,给出了能够满足泵浦光束与双包层掺杂光纤内包层模场分布匹配条件的透镜组参数及其位置参数设计要求,并利用结构参数与双包层掺杂光纤完全相同的未掺杂双包层光纤进行了耦合功率的实验测试,当泵浦源输出功率为50 W时,获得了34.1 W的入纤泵浦功率,泵浦耦合效率达到近70%,为搭建双包层光纤激光器奠定了基础.     

15 kW光纤耦合半导体激光淬火光源

针对激光淬火在大型风电轴承生产中的实际需求,研制了一种功率高达15 kW的光纤耦合半导体激光淬火光源。该光源先采用915 nm和976 nm两个波段各8个宏通道冷却技术封装的半导体激光微巴条阵列作为发光单元,进行空间、偏振及波长合束,在光纤芯径为200μm、数值孔径为0.22的光纤中实现了超过800 W的连续输出,电光转换效率整体达到45%以上。再通过19×1光纤合束器对19个800 W模块进行合束,由输出端口光纤直径为1 mm的光纤耦合输出。光束经过由微透镜阵列与聚焦镜复合的加工头,光斑匀化,最终输出了功率大于15 kW、光斑尺寸为165 mm×25 mm的激光束,满足了大型风电主轴轴承滚道面淬火需求。     

光通信用的发光二极管

我们研制了光纤通信用的高亮度发光二极管。这种二级管是一种带光波导层的 GaAlAs-GaAs 端面辐射型结构。辐射率高达500W/球面度·厘米~2,耦合到光纤中的功率大于100μW。调制带宽为25MH_Z。由加速老化试验外推,寿命达几十万小时。也研究了带光纤封装的发光二极管。将耦合用的光纤尾端作成锥形,大大改善了耦合效率,用 NA=0.27的光纤,得到了560μW 的输入功率。     

基于偏振折叠的光纤耦合实验研究

基于二极管激光器mini-bar的光纤耦合方式是一种降低耦合系统成本并提高整体转换效率的方法。提出一种偏振折叠的光束整形方式,并采用一种CW 50 W mini-bar进行了相关耦合系统的设计。针对mini-bar的特殊结构与散热需求,设计了针对mini-bar封装用的特种微通道冷却器,并通过封装实验结果验证设计有效。将10片封装在铜微通道冷却器上的CW 50W mini-bar组装成两列各5 bar的叠阵,实现了两列叠阵的激光束沿快轴方向的空间合成,合成后输出功率439 W,空间耦合效率97%。根据耦合系统的设计进行了400μm芯径、0.22 NA的光纤耦合实验,得到光纤输出端脉冲激光功率186.9 W,整体光光效率为52.2%。     

一种实现半导体激光器和多模光纤耦合的实用技术

文中提出了一种实现半导体激光器和多模光纤耦合的实用化方法。用一段直径为600μm的裸石英光纤代替柱透镜对半导体激光器输出光束进行准直整形;用半球端光纤对光束进行聚焦后直接实现和光纤耦合,来代替聚焦透镜和光纤耦合的环节。研究表明:采用该方法耦合效率在80. 0%左右,同时最大程度解决了使用柱透镜和聚焦透镜的组合透镜耦合系统时存在的调试与封装困难的问题,且工艺稳定,因而有着广泛的应用前景。     

974nm半导体激光器的光纤耦合研究

根据半导体激光器和单模光纤模场分布特点,用模式耦合理论研究了单模光纤与半导体激光器的耦合,结果表明将光纤端面制作成楔形微透镜可以使光纤与半导体激光器的耦合满足模场匹配和相位匹配的要求。用遗传算法对楔形光纤微透镜参数进行优化,得到楔角为88°,柱透镜半径为3.44μm,耦合距离为6.13μm时耦合效率达到最佳值,用Zemax光学仿真软件对耦合模型进行仿真,得到耦合效率为88.9%,耦合好的模块经激光点焊及高低温环境测试后,得到最大耦合效率为81.36%。实验结果与仿真结果相差不大,耦合输出功率满足了作为光纤激光器种子源的功率要求。     

出纤功率30W的激光二极管线列阵光纤耦合器件

用一根柱透镜对大功率半导体激光器线列阵输出光束的快轴方向进行准直,准直后的光束耦合到光纤列阵中.大功率半导体激光二极管线列阵的输出功率为40W,线列阵有19个发光单元,每个发光单元的发光区面积为100μm×1μm.大功率激光二极管线列阵耦合后出纤功率为30W,耦合效率为75%,光纤的数值孔径为0.11.     

A novel inspection of fiber post-weld-shift in butterfly laser module packaging

Butterfly packaging technology with a fiber pigtail is widely used in packaging optical modules, and laser welding is used to join components in a butterfly package. During laser welding, the rapid solidification of the welded region and the associated shrinkage of material are expected cause relative movement between prealigned components. Such a post-weld-shift (PWS) might significantly reduce the efficiency of light coupling. The laser hammer technique can be used to realign fiber that shifts during laser welding, and it requires that the fiber shift be measured in three directions. Measuring the shift along the Y axis is difficult because space is limited. In this paper, a reflector placed near the fiber during laser welding was used to determine the shift along the Y-axis. The fiber images obtained using the charge-coupled device (CCD) camera were sometimes deformed, so digital image processing was used to calibrate the deformed images and calculate the fiber shift along three axes. The experimental results indicate that the fiber shift along the Y-axis, when captured using reflector inspection could be measured precisely, and more strongly influenced power coupling loss than shifts in the other two directions. The results are useful in implementing the realignment method after butterfly packaging.     

应用于金属焊接的光纤耦合输出2kW半导体激光光源

报道了一种高效节能、千瓦级光纤柔性输出半导体激光焊接光源。采用半导体激光合束技术,研制出2246W半导体激光合束光源,电光效率达43.6%;通过聚焦耦合,实现从600μm芯径、数值孔径0.2的光纤连续输出功率为2104W,光纤耦合效率达93.7%;在光纤输出端采用放大率1颐1的成像系统,到达工件表面的功率为2084W,光参量积为46.89mm·mrad,在束腰处测得光斑直径600μm,光功率密度为7.37×105 W/cm2,可以满足金属薄板焊接的激光加工要求     

光电器件激光焊接封装焊后位移的有限元分析和实验观测

建立了晶体管外形罐(TO-can,transistor outline-can)型LD激光焊接封装的三维有限元模型,利用热-结构耦合分析方法,对焊后位移(PWS)进行数值模拟.分析结果表明:焊点位置对称时,其能量差别越大,PWS越大,PWS朝向能量合成的方向;3个焊点的位置不对称引起的PWS较小,主要是轴向位移.PWS特征的理论分析得到了实验结果的证实,因此有限元方法可以有效预测PWS.     

大功率激光二极管高亮度、高功率密度光纤耦合

将条宽为100μm,有源区厚度为1μm的大功率激光二极管(LD)的输出光束高效地耦合到芯径是50μm的多模光纤中,得到了高亮度、高功率密度的光纤输出.功率密度高达3.6×104W/cm2,耦合效率为70%.LD输出光束的发散角较大并且存在较大的像散,因此耦合系统中需要结构复杂、性能可靠的微透镜.采用在一个玻璃衬底上,具有两个不同曲率半径的双曲面透镜实现LD与多模光纤的耦合.     

Improved coupling efficiency of a strained InGaAs-AlGaAs quantum-well laser into a fiber Bragg grating

We describe a highly efficient coupling of up to 78% into a single mode fiber (SMF) by utilizing a low-divergence-angle InGaAs-AlGaAs laser and a new high-NA aspheric lens, resulting in the coupled optical output of over 300 mW with a kink-free performance. The kink-free 300 mW of fiber-coupled power is the largest power reported from a diode laser wavelength stabilized using a fiber Bragg grating. A 3% fiber Bragg grating makes the optical output stabilize at a wavelength of 1.016 /spl mu/m for an optical output power up to 310 mW and without any distinct decrease of the optical output. The coupling tolerance for lateral offsets is improved by utilizing a thermal-diffused expanded-core technique even in the case of using a high-NA coupling aspheric lens. We have also achieved a 300-mW fiber-coupled wavelength-stabilized InGaAs-AlGaAs semiconductor laser butterfly module using a fiber Bragg grating.     

Fabrication of semiconductor optical switch module using laser welding technique

The 4/spl times/4, 1/spl times/2, and 1/spl times/4 semiconductor optic-switch modules for 1550 nm optical communication systems were fabricated by using the laser welding technique based on the 30-pin butterfly package. For better coupling efficiency between a switch chip and an optical fiber, tapered fibers of 10-15 /spl mu/m lens radius were used to provide the coupling efficiency up to 60%. The lens to lens distance of the assembled tapered fiber array was controlled within /spl plusmn/1.0 /spl mu/m. A laser hammering technique was introduced to adjust the radial shift, which was critical to obtain comparable optical coupling efficiencies from all the channels at the same time. The fabricated optical switch modules showed good thermal stability, with less than 5% degradation after a 200 thermal cycling. The transmission characteristics of the 4/spl times/4 switch module showed good sensitivities, providing error free transmissions below -30 dBm for all the switching paths. The dynamic ranges for the 4/spl times/4 and 1/spl times/2 switch modules were about 8 dB for a 3 dB penalty and about 17 dB for a 2 dB penalty, respectively.     

Design of a miniature lens for semiconductor laser to single-mode fiber coupling

A design method for a miniature optical lens tipped on a single-mode fiber end to improve power coupling from a semiconductor laser is described. The lens shapes studied are hemispherical, hemicylindrical, and hemiellipsoidal. The optimum coupling conditions and the obtained coupling efficiency are represented in terms of laser beam and fiber parameters. Preferable ranges of hemispherical and hemicylindrical lenses are classified according to the laser and fiber mode spot sizes. Fiber axis offset and tilt effects on coupling efficiency are also studied.