有源光缆中光路耦合系统的设计

发布时间：2018-06-22 14:03

本文选题：有源光缆 + 模式耦合　；参考：《南京邮电大学》2017年硕士论文

【摘要】：随着互联网+时代数据的快速交换,有源光缆(AOC)集成了多模光纤光缆、光收发模组和控制芯片等,具有传输容量大、能耗低等优势,是数据中心、高性能计算机群等领域理想的光互连线缆。本文研究芯片托盘型垂直腔面发射激光器(VCSEL)与多模光纤(MMF)的耦合问题,首先在模式耦合理论基础上,采用重叠积分法,构造了计算VCSEL横模与MMF模场的能量耦合效率数学模型。利用数值软件MATLAB计算了:(1)当VCSEL与MMF直接对准耦合时,计算通信级VCSEL辐射的低四阶横模与MMF模场的能量耦合效率;(2)当VCSEL中心与MMF轴心间发生纵、横向位移时,计算分析了01横模与MMF的01、02、11模场能量耦合效率,计算结果表明,当VCSEL与MMF两轴心横向偏移7.5μm时,两者的耦合效率为50%,当VCSEL与MMF间轴向位移从0mm增大到1mm处,两者的耦合效率下降到8%。考虑芯片托盘型VCSEL与MMF之间存在一定位移,为了提高两者的耦合效率,利用光学软件ZEMAX优化设计了曲率半径为2.549mm,中心厚度为2mm的非球面透镜耦合系统,并在光学分析软件TRACEPRO中仿真从光源到光纤的实际耦合光路,仿真结果表明,当VCSEL出射端面与MMF入射端面分别位于两透镜的焦点处时,耦合效率为86%,同时,VCSEL芯片中心相对MMF入射端面的轴心横向偏移10μm时,VCSEL与MMF的耦合效率下降到56%。根据TP中的仿真系统,搭建实际传输光路系统,并对系统进行相关数据测量,(1)VCSEL与MMF之间未加耦合透镜系统,两者的中心相对横向偏移从0μm到20μm时,耦合效率从4.7%下降到0.12%;(2)VCSEL与MMF之间加耦合透镜系统,两者的中心相对横向偏移从0μm到20μm时,耦合效率从84%下降到25%,当耦合对准时,设计的透镜耦合系统使两者的耦合效率提高79%。由于光学元件对光束的吸收、散射及端面反射等因素影响,实验数据略小于理论计算,实验结果表明,芯片焊接过程中,应尽量避免VCSEL芯片的横向偏移,控制误差在?3μm内。
[Abstract]:With the rapid exchange of data in the Internet era, active Optical Cable (AOC) integrates multi-mode optical fiber optic cables, optical transceiver modules and control chips. It has the advantages of large transmission capacity, low energy consumption, and is the data center. High performance computer cluster and other fields ideal optical interconnection cable. In this paper, the coupling problem between chip tray type vertical cavity surface emitting laser (VCSEL) and multimode fiber (MMF) is studied. Firstly, based on the mode coupling theory, a mathematical model for calculating the energy coupling efficiency of VCSEL transverse mode and MMF mode field is constructed by using overlapping integration method. The results are as follows: (1) when the VCSEL and MMF are aligned directly, the energy coupling efficiency of the low fourth order transverse mode and the MMF mode field of the VCSEL radiation is calculated, and (2) when the longitudinal and transverse displacement occurs between the VCSEL center and the MMF axis, the energy coupling efficiency of the low fourth order transverse mode and the MMF mode field of the communication level VCSEL radiation is calculated when the VCSEL center is aligned directly with the MMF. The field energy coupling efficiency of 01 transverse mode and MMF is calculated and analyzed. The calculated results show that the coupling efficiency is 50 when the transverse shift between VCSEL and MMF is 7.5 渭 m, and when the axial displacement between VCSEL and MMF increases from 0mm to 1mm. The coupling efficiency of the two decreases to 8%. Considering the displacement between chip tray type VCSEL and MMF, in order to improve the coupling efficiency, an aspheric lens coupling system with curvature radius of 2.549 mm and center thickness of 2mm is designed by using optical software ZEMAX. The optical analysis software TRACEPRO is used to simulate the actual coupling optical path from the light source to the fiber. The simulation results show that the VCSEL exit end and the MMF incident end are located at the focal point of the two lenses, respectively. The coupling efficiency is 86 and the coupling efficiency of VCSEL and MMF decreases to 56m when the center of VCSEL chip is shifted 10 渭 m from the axial center of the incident end of MMF. According to the simulation system in TP, the actual transmission optical path system is built, and the relevant data are measured. (1) the uncoupled lens system between VCSEL and MMF, when the center of the two systems is relatively lateral offset from 0 渭 m to 20 渭 m, The coupling efficiency decreases from 4.7% to 0.12. (2) when the center relative lateral deviation of VCSEL and MMF increases from 0 渭 m to 20 渭 m, the coupling efficiency decreases from 84% to 25 parts. Due to the influence of optical elements on beam absorption, scattering and end reflection, the experimental data are slightly smaller than theoretical calculation. The experimental results show that the transverse migration of VCSEL chip should be avoided and the control error is within 3 渭 m during chip welding.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN818

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