【作者】 熊凌云；

【导师】 开桂云；

【作者基本信息】 南开大学 ， 光学， 2004， 硕士

【摘要】 随着人类社会步入信息化时代,对通信的需求呈现飞速增长的趋势,波分复用(WDM)通信技术应运而生。目前,WDM系统的发展呈现出以下两大趋势:一方面,WDM正在由点到点传输系统向WDM全光网发展。光分插复用器(OADM)能够在光域上实现信号的上下载,克服了传统技术的电子瓶颈,是实现WDM全光网的关键技术。另一方面,WDM通信系统正朝着信道数目越来越多的方向发展。为了降低成本,以多波长激光器作为通信系统光源成为必由之路。在各类多波长激光器中,多波长掺铒光纤激光器(MW-EDFL)以其众多优点成为了研究热点。本论文以基于光纤光栅的可编程OADM和多波长掺铒光纤激光器作为主要研究对象,进行了以下研究工作:1.利用耦合模理论分别对光纤布喇格光栅和双折射光纤布喇格光栅的光谱特性进行了分析和计算机模拟。探讨了光纤布喇格光栅的轴向应变调谐和横向应变调谐机理,并对两种调谐技术给出了理论分析结果。2.比较系统的总结了可编程OADM的发展现状、结构,以及其应用前景。同时分析了各种可编程OADM的优点、缺点,结合几种方案的典型产品,对可编程OADM的应用前景做了展望。3.研制了基于光纤布喇格光栅和环形器的可编程OADM。光纤光栅采用压电陶瓷调谐方案,以光谱仪作为信道监测,计算机为控制中心,较好地实现了可编程OADM的实验及其相关测试。其中,利用4波长掺铒光纤激光器对所研制的可编程OADM测试,其上下载波长分别为1550.02nm,1550.82nm,1551.62nm,1552.42nm,间隔0.8nm,调谐速度在1s左右,相邻信道隔离度达到21.5dB,实现了对上下载波长的控制与监视。4.介绍了线形腔光纤激光器和环形腔光纤激光器的基本理论以及多波长激光器稳定振荡的条件,并总结了几种实现多波长掺铒光纤激光器的稳定振荡的方法。5.对多波长掺铒光纤激光器进行了实验研究。分别利用三种方案实现了常温下稳定激光输出的结构新颖、简单实用的多波长掺铒光纤激光器:(1)通过调谐装置提供轴向应变和横向应变,分别利用双折射光纤光栅和单模光纤光栅作为激光的选频器件,实现了波长及波长间隔可调谐的双波长掺铒光纤激光器。(2)利用双折射光纤和起偏器组成的周期滤波器,通过偏振烧孔效应抑制由均匀展宽引起的模式竞争,实现了室温下稳定激光输出的可调谐双波长掺铒光纤激光器。激光器可以实现波长间隔分别为3.44nm和1.56nm的双波长激光输出,此外,该激光器还能获得波长调谐在1599.28nm-1605.84nm范围内的单波长激光输出。(3)利用双折射光纤环形镜作为反射镜,结合起偏器在激光腔内引入偏振更多还原

【Abstract】 With the advent of information era, human society’s increasing demand for communication capacity causes the introduction of Wavelength-Division Multiplexing (WDM). In present, WDM communication system is developed towards two directions. On one hand, WDM system is transforming from the point to point system to all optical networks. Optical Add/Drop Multiplexer (OADM), which has a capacity of add/drop signals in the optical formation and then avoids the drawback of electronic bottleneck demonstrated in traditional technology, becomes the pivot to realize all optical WDM networks. On the other hand, the number of signal channels keeps increasing with the development of WDM communication system. Due to their economic cost, it is an indispensable way to utilize multiwavelength lasers as signal emitters in communication system in order. Multiwavelength Erbium-doped fiber lasers (MW-EDFLs) become the research focus out of various types of multiwavelength lasers for their attracting merits. This dissertation emphasizes on the study of fiber Bragg grating (FBG) based Programmable OADM and Multiwavelength erbium-doped fiber lasers, and includes the detail descriptions on the following subjects:1. The spectra characteristics of both the single mode fiber Bragg grating and the hi-birefringence fiber Bragg grating are analyzed and simulated with coupled-mode theory. The reflection wavelength tuning of FBGs by applying axial strain and lateral strain is discussed, and the theoretic results in both of the above situations are presented.2. The development status and structures of programmable OADMs are generalized in brief. Programmable OADM’s future application is prospected after analyzing merits and shortcomings of several typical POADM schemes3. A POADM based on FBG and optical circulator is developed. By tuning the FBG glued on a piezoelectric transducer, and monitoring the spectra at download ports by an optical spectra analyzer through computer management, we realize a programmable OADM. Tested by Four-wavelength laser, its add/drop wavelengths are 1550.02nm, 1550.82nm, 1551.62nm, 1552.42nm with wavelength space of 0.8nm, tuning speed reaches about 1s, and isolation between adjacent channels is 21.5dB. Monitor and control can be easily executed from the system interface.4. The fundamental principles of both the linear cavity fiber laser and the ring cavity fiber laser and the stability criterion for multiwavelength oscillations are introduced. Several kinds of techniques to achieve mulitwavelength oscillations are summarized.更多还原