光纤传感测量中耦合系统的设计

根据光纤传感测量中光源的选取原则,将半导体激光器作为光纤传感器的光源并选取单模光纤作为尾纤,基于光学设计软件Zemax纯非序列光学系统,设计了一种半导体激光器与单模光纤的耦合系统。通过分析半导体激光器的光束特性及半导体激光器与单模光纤的耦合模场理论,由一个球透镜和一个准直透镜构成组合透镜耦合方式,达到提高耦合效率和容忍度的目的。设计时在非序列光学系统下进行了百万次光线追迹,仿真得到所设计系统的耦合效率为78%左右,而实验测试结果为69.11%,由此对误差产生的原因进行了分析。     

10Gb/s高速光器件激光器端耦合模型设计与优化

为提高半导体激光器与单模光纤的耦合效率,提高信噪比,延长光信号在光纤中传输的距离,利用光学仿真软件首先针对10G-EPON(万兆光无源网络)光器件建立了一种新的耦合模型并对其进行了仿真优化,其次分析了新模型与原有模型耦合效率出现差异的原因,最后探讨了透镜封装尺寸误差与耦合效率的关系,并对结果进行了归一化处理。研究发现:经过百万次光线追迹,模型的最大耦合效率为63.53%,在光电器件同样采用同轴型封装的情况下,与传统的球透镜耦合相比,改进模型的耦合效率提高了约16.68%;耦合效率的高低取决于半导体激光器整形后光斑的模场与单模光纤模场的匹配程度;耦合效率对透镜距离变化的敏感程度依次为快轴准直透镜非球面透镜慢轴准直透镜。研究结果可为10Gb/sEML光器件的实物设计封装提供尺寸参考和建议。     

微型透镜元件的最新动向

一、前言微型透镜元件在光通信领域中的应用最初是作为半导体激光器与光纤耦合的耦合透镜而发展起来的。最近,随着光盘等在信息记录再现领域中的应用迅速扩展,物镜和准直透镜作为光敏元件开始得到大量使用。因此,     

808nm高亮度半导体激光器光纤耦合器件

针对单个808nm单管半导体激光器输出功率低,采用端面泵浦方式对光纤激光器进行泵浦时受到限制的问题,本文利用空间合束技术制成高亮度半导体激光器光纤耦合模块来提高808nm单管半导体激光器泵浦掺Nd3+双包层光纤激光器的效率。首先,通过微透镜对每个单管半导体激光器进行快慢轴准直;然后,使用反射棱镜对每个激光器发出的光进行空间合束;最后,利用自行设计的扩束系统将合束后的光束进行扩束,聚焦进入光纤,从而极大地提高光纤耦合模块的亮度。实验中将4只连续输出功率为5W的单管半导体激光器发出的光束耦合进芯径为105μm、数值孔径(NA)为0.2的光纤,当工作电流为5.8A时,通过光纤输出的功率为15.22W,耦合效率达到74%,亮度超过1.4MW/cm2.sr。     

808 nm high brightness module of fiber coupled diode laser

针对单个808 nm单管半导体激光器输出功率低,采用端面泵浦方式对光纤激光器进行泵浦时受到限制的问题,本文利用空间合束技术制成高亮度半导体激光器光纤耦合模块来提高808 nm单管半导体激光器泵浦掺Nd3+双包层光纤激光器的效率.首先,通过微透镜对每个单管半导体激光器进行快慢轴准直;然后,使用反射棱镜对每个激光器发出的光进行空间合束;最后,利用自行设计的扩束系统将合束后的光束进行扩束,聚焦进入光纤,从而极大地提高光纤耦合模块的亮度.实验中将4只连续输出功率为5W的单管半导体激光器发出的光束耦合进芯径为105 μm、数值孔径(NA)为0.2的光纤,当工作电流为5.8A时,通过光纤输出的功率为15.22W,耦合效率达到74％,亮度超过1.4 MW/cm2·sr.     

大屏幕激光显示系统中光纤混色技术的耦合过程分析

介绍了在大屏幕激光显示系统中光纤混色技术的原理，并且通过实验方法讨论了在激光和光纤耦合过程中透镜的选择、数值孔径的匹配、消色差组合透镜的作用、对入射光线的要求和光能的损失等问题，从而能提高激光经光纤混色后的光束成象质量。     

塑料光纤微透镜耦合平头发光二极管

为了有效耦合平头发光二极管(LED),使用机械方法加工了锥球面塑料光纤(POF)微透镜。平头发光二极管由圆头发光二极管打磨掉聚光帽制得,其出光端面与芯片距离小于0.5mm。锥球面塑料光纤微透镜用数控机床加工制得。采用光线追迹法对耦合模型进行了分析。实验优化了锥球面光纤微透镜的参数、锥角、小球半径、工作距离和单端/双端模式,并理论分析了双端锥球面微透镜耦合的实验结果。当双端锥球面光纤微透镜锥角为140°、小球半径为0.15mm时,可带来20.4%的耦合效率增益。所用加工方法有利于微透镜参数优化,具有较好的加工精度和重现性,可以用于制作塑料光纤微透镜。     

基于半导体激光短阵列的976 nm高功率光纤耦合模块

采用12只出射波长为976 nm的传导冷却半导体激光短阵列为发光单元,研制出了百瓦级高功率光纤耦合模块.首先,利用光束转换器(BTS)和柱透镜对每只半导体激光短阵列进行光束整形,使得快慢轴方向光束质量接近并且发散角相同;然后,应用空间合束技术将每6只半导体激光短阵列在垂直方向上叠加,形成一个激光组,并利用偏振分束器(PBS)将两个激光组偏振合束;最后利用优化设计的三片式聚焦镜将激光耦合到光纤中.实验结果表明:该光纤模块的连续输出激光功率可达418.9 W,光纤芯径仅为400 μm,数值孔径(NA)为0.22,由此可得到激光亮度为2.19 MW/(cm2·str).利用Matlab软件分析光纤出射的光束形貌为平顶分布,显示其适合用于金属材料的硬化和焊接等领域.最后测量了模块的光谱,电流从20 A增加到50 A时,激光的峰值波长漂移了6.8 nm,并且在50 A时光谱宽度为4.12nm,表明该光纤耦合模块散热良好.同其它类型激光器相比,本激光模块电光转换效率和出光功率高,适用于材料加工和泵浦光纤激光器等领域.     

FGZ-8半导体激光治疗机设计与研制

采用二合一光纤系统、高效率光纤耦合装置、Al Ga In P半导体激光器、方便适用的光纤定位装置以及稳定可靠的电源控制系统 ,研制了一种新型 6 5 0 nm半导体激光治疗仪 ,其光纤端输出达 10 9m W。该仪器已在生物医学领域成功应用。     

Er3+/Yb3+共掺双包层光纤的高功率L-band 光纤激光器的实验研究

采用端面泵浦的方式,用尾纤输出波长为976 nm的高亮度多模半导体激光器, 包层泵浦的铒镱共掺双包层大模面积光纤,非球面镜组耦合系统,进行了共掺双包层光纤的高功率L-band光纤激光器的研究,泵浦耦合效率达到了62%以上,并在F-P激光振荡腔中实现了高效的连续激光输出。在光纤长度为30 m、入纤功率为 13.41 W时,首次报道输出连续功率达到了4.3 W。激光器的斜率效率为44％, 激光输出中心波长1 603 nm。     

A lensed fiber workstation based on the elastic polishing plate method

Integrated coupling between laser source (such as laser diodes, LD’s) and single-mode fibers (SMFs) is one of the most important and fundamental techniques of optical communications. Lensed fibers have desirable features for the coupling scheme, such as compactness, simplicity, stability, and freedom from bulky lenses. However, the high precision lens geometry is required for lensed fibers. In this study, we present a lensed fiber fabrication workstation based on the elastic polishing plate mechanism. A theoretical model was also proposed in order to simulate the fiber lapping condition. The results show that the lensed fiber’s dome radius is mainly controlled by the accumulated lapping time, Preston’s coefficient, and selection of rubber pad material. The lapping time control is demonstrated as a preferred working parameter and thus is implemented in our fiber workstation.     

Lensed plastic optical fiber employing hyperbolic end filled with high-index resin using electrostatic force

The step-index (SI) and graded-index (GI) plastic optical fibers (POFs) are strong candidates for short-distance transmission, fiber-to-the-home (FTTH) networks, automobile applications and interchip interconnections. The GI POFs which has been proven to reach distances as long as 1 km at 1.25 Gb/s has a relatively low NA. Therefore, the efficient coupling of GI POFs to the light source has become critical to the power budget in the system. Forming a lens-like structure directly on the fiber end is preferred for simplicity of fabrication and packaging, such as polishing and fusion, combing different fibers with the cascaded fiber method and hydroflouride (HF) chemical etching. These approaches are well established, but applicable only to glass. This work proposes a novel structure of a lensed plastic optical fiber (LPOF). The fabrication of the LPOF is demonstrated and the coupling efficiency exceeds 72%.     

Lensed plastic optical fiber with an aspherical fiber end formed by joining an aspherical plastic lens and a plastic optical fiber using laser transmission welding

In optical communication systems which require the coupling of the light source to the fiber, efficient coupling can be practically realized either using a separate lens or by direct formation of the lens at the fiber end. A novel lensed plastic optical fiber (LPOF) is presented with efficient coupling of the plastic optical fibers with a light source. An aspherical plastic lens was bound with a flattened plastic fiber end by laser transmission welding (LTW) to form an aspherical fiber endface which can provide better coupling efficiency than a spherical fiberface. An analysis demonstrates that LTW can offer strong welding with small heat affected zones that are appropriate for commercial use. In this study a useful method for manufacturing lensed-end fibers is developed and demonstrated experimentally.     

模式搜索法在光纤有源自动对准中的应用

提出基于模式搜索法的光纤有源自动对准算法,实现了多自由度同时寻优,解决了不同自由度之间的交叉耦合问题,提高了对准速度和对准精度。通过仿真与实验研究,与传统的爬山法进行对比。仿真结果表明,激光二极管与单模光纤五自由度对准时,模式搜索法只需20次迭代就可以找到最大点,收敛速度是爬山法的9倍。实验结果证明,横向调整两个自由度对准时,模式搜索法搜索速度比爬山法平均快10 s,定位成功率达到90%。     

六轴运动平台几何误差与阵列光纤对准精度的映射关系

针对光缆中阵列光纤与波导芯片精准对接问题,运用光电子封装系统六轴精密运动平台,研究了控制阵列光纤的位姿及对准精度。依据齐次坐标矩阵的几何误差模型,采用方差敏感性分析方法,辨识得出影响对准精度的重要误差项;分析了运动平台的搭建结构,探讨了运动平台几何误差与光纤对准精度的映射规律。实验结果表明,该方法可靠、有效,可为提高光纤封装效率与对准效率提供参考。     

半电极压电纤维能量收集建模与仿真

为改善圆柱形压电纤维的发电能力,对其进行理论分析,建立了半电极压电纤维的能量收集效率与纤维截面内外径比、外部压电层与金属芯柔度比及纤维的机电耦合系数之间的关系。使用数学建模的方法,讨论了收集效率与这三个参数之间的理论方程,并且进行仿真实验。结果表明:在纯弯矩作用下半电极压电纤维的能量收集效率随着机电耦合系数的增大而提高,随柔度系数比的增大而减小,随着半径比的增大先增大后减小。     

High precision optical fiber alignment using tube laser bending

In this paper, we present a method to align optical fibers within 0.2 μm of the optimal position, using tube laser bending and in situ measuring of the coupling efficiency. For near-UV wavelengths, passive alignment of the fibers with respect to the waveguides on photonic integrated circuit chips does not suffice. In prior research, it was shown that permanent position adjustments to an optical fiber by tube laser bending meets the accuracy requirements for this application. This iterative alignment can be done after any assembly steps. A method was developed previously that selects the optimal laser power and laser spot position on the tube, to minimize the number of iterations required to reach the target position. In this paper, that method is extended to the case where the absolute position of the fiber tip cannot be measured. By exploiting the thermal expansion motion at a relatively low laser power, the fiber tip can be moved without permanent deformation (only elastic strain) of the tube. An algorithm has been developed to search for the optimal fiber position, by actively measuring and maximizing the coupling efficiency. This search is performed before each bending step. Experiments have shown that it is possible to align the fiber with an accuracy of 0.2 μm using this approach.     

光电互联电路中激光器与光纤间接耦合仿真分析

随着大数据、云计算、5G 通信等新兴产业的蓬勃发展,数据中心的信息量成指数增长。光电互联电路可实现数据中心服务器内部板间、组件之间、芯片之间的高速、高带宽、高密度、低功耗、低损耗的信息传输,可有效解决高速电互联技术的传输瓶颈。采用光纤作为传输介质可有效降低光电互联电路的制作成本,激光器与光纤的耦合对准技术则是实现光电互联电路的关键技术之一。文中利用ZEMAX光学软件建立了激光器与光纤间接耦合模型,仿真分析了激光器纵向偏移误差、横向偏移误差、角度偏移误差和45°耦合机构倾斜角角度加工误差对耦合效率的影响。仿真结果可为光电互联电路的设计与制造提供指导。     

镀金属膜长周期光纤光栅的传感特性

本文基于耦合模理论, 建立了严格的四层金属膜理论模型, 探讨了镀金属膜长周期光纤光栅(Long-period fiber grating, LPFG)的温度、 应变及折射率特性, 以及镀膜参数对镀金属膜长周期光纤光栅光谱特性的影响.仿真结果表明, 长周期光纤光栅表面最优的金属膜厚度将引起表现等离子共振(Surface-plasmon resonance, SPR)特性, 这一特性将使得LPFG 对稳定及折射率都有较高的敏感性, 而对应变影响较小. 理论分析表明, 银膜厚度在0.8-1.2 nm 范围内时, 折射率敏感度达到最大值为42.402 6, 敏感度增加4.5%. 仿真结果为镀膜长周期光纤光栅的设计及参数优化提供了理论指导.