【作者】 刘规东；

【导师】 曲轶；

【作者基本信息】 长春理工大学 ， 物理电子学， 2010， 硕士

【摘要】 光纤通信系统中的密集波分复用(DWDM)技术对发射光源有很高的要求,要求发射波长精确、输出线宽窄等。光纤光栅外腔半导体激光器在很大程度上能够符合DWDM光纤通信系统的要求,近些年来成为该领域的一个研究热点;980hm半导体激光器被广泛应用于泵浦掺饵光纤放大器,它与单模光纤(SMF)通过合理的模型耦合,不仅能改善掺饵光纤放大器的性能,而且直接影响光纤传输的中继距离,因而日益受到人们的重视。本论文采用楔形柱透镜光纤光栅(FBG)形成外腔,获得了激射波长稳定的980nm光纤光栅外腔半导体激光器。其主要内容可概括如下:(1)对光纤光栅外腔半导体激光器的工作原理作了详细的分析,包括发光机制、模式选择理论、等效腔理论、速率方程、激光器与光纤的耦合理论等。(2)基于等效腔理论,考虑半导体激光器端面反射率、外腔长度及光纤光栅三者的共同作用,利用Matlab仿真模拟了它们对光纤光栅外腔半导体激光器输出特性(如阈值增益、输出功率、线宽和边模抑制比)的影响,并获得了优化的参数。(3)分析了均匀光纤布拉格光栅的光学特性,结合优化的光纤光栅反射率,确定了光纤光栅其它参数,包括周期、长度。(4)针对980nm半导体激光器与楔形柱透镜光纤耦合,利用matlab软件仿真计算得出优化的光纤微透镜参数(楔形柱透镜曲率半径和半楔角)及激光器与透镜光纤端的最佳距离。(5)介绍980hm光纤光栅外腔半导体激光器的蝶形模块封装工艺。(6)通过对器件输出特性的测试来证实理论计算出的优化模型的准确性。更多还原

【Abstract】 Dense wavelength division multiplexing (DWDM) is an important technology of fiber communication system. The laser source, as the important portion of DWDM optical fiber communication system, must satisfy some strict requirements such as stable lasing wavelength, and narrow line-width, etc. Fiber grating external cavity semiconductor laser (FGESL) has received considerable attention as a promising source to satisfy these strict requirements; 980nm semiconductor laser is widely used in the design of erbium doped fiber amplifier(EDFA). The coupling efficiency of 980 semiconductor laser and single mode fiber (SMF) has become the most fundamental problem for engineers and researchers to solve. Coupling efficiency affects the performance of EDFA and decides fiber communication relay distance. Thus people pay more and more attention on researching it.In this paper, we used wedge-shaped cylindrical lensed fiber bragg grating (FBG) to form an fiber grating external cavity semiconductor laser, finally we obtained stable lasing wavelength output. The theoretical and experimental researches completed in the thesis are as follows:(1) Made a detailed analysis to the work principle of FGB external cavity semiconductor laser, included luminescent mechanism, mode selection theory, equivalent cavity theory, speed equation, fiber coupling theory and so on.(2) Based on the equivalent cavity theory, we took semiconductor laser’s end surface reflectivity, external cavity length and fiber grating together into account, simulating and calculating basic parameters of fiber grating external cavity semiconductor laser by Matlab software, such as: threshold gain, output power, line width and side-mode suppression ratio, then we obtain the optimized parameters.(3) Analyzed the characteristics of fiber Bragg grating, and used the optimized reflectivity of fiber grating, we determined other parameters of fiber grating , including its cycle, length.(4) Aimed at 980nm semiconductor laser coupling with wedge-shaped cylindrical lensed fiber, through the coupling equation, we simulated and attained optimized parameters of micro lensed fiber (half wede angle and curvature radius) and the best distance between them by Matlab software. (5) Introduced the butterfly-shaped packaging for 980nm fiber grating external cavity semiconductor laser.(6) Through testing the output characteristics of 980nm fiber grating external cavity semiconductor laser to confirm the optimization model was accurate.更多还原