共查询到20条相似文献,搜索用时 15 毫秒
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J. P. CARVALHO R. ROMERO M. MELO L. A. GOMES O. FRAZÃO M. B. MARQUES 《Fiber and Integrated Optics》2013,32(3-4):371-394
Abstract The current status of the research and development as well as the recent contributions in optical communications at INESC Porto is reviewed. This review includes all the work carried out in the last few years in optical fiber communications, namely the development of passive and active optical devices. Some of the passive structures that have been studied and developed are: add-drop multiplexers, multiplexer/demultiplexer based on Bragg grating technology, dispersion compensators, and optical cross-connects. Active photonic devices such as wavelength converters, fiber lasers, and fiber amplifiers have also been studied. New ideas are being continuously developed and tested. 相似文献
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Lin Zhu Guozhong Wang Li Xia Shizhong Xie 《International Journal of Infrared and Millimeter Waves》2002,23(3):465-473
Chirped fiber Bragg grating (CBG) has been used to compensate the dispersion in the optical fiber communication system. We substitute dispersion compensation fiber (DCF) with CBG in the 10Gbit/s disperion-managed system over 1100km. In order to get system performance in the nonideal situation, the parameters of CBG are varied from the designed optimum in some extent. Post-, pre- and dual-compensation methods are compared. 相似文献
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SHU Xuewen SHI Wei JIANG Shan HUANG Dexiu 《Chinese Journal of Lasers》2000,9(4):319-324
1 Introduction Fibergratingsareprovedtobeoneofthemostimportantrecentdevelopmentsinthefieldofopticalfibertelecommunicationsandsensing .Theyarelikelytohaveapplicationintwomainareas:dispersioncompensationinlong haulfibernetworks[1,2 ]andwavelengthroutinginw… 相似文献
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基于高双折射光纤布拉格光栅的自动增益控制掺铒光纤放大器 总被引:3,自引:0,他引:3
掺铒光纤非均匀展宽引起的空间烧孔现象导致单波长激光并不能完全控制放大器增益,提出了一种新颖的自动增益控制掺铒光纤放大器的结构:即采用高双折射光纤布拉格光栅产生抽运光,其写制光栅的波峰对应的波长分别为1549.3 nm和1549.83 nm,波长间隔为0.53 nm。通过调整偏振控制器,就实现了单激光或双激光的增益控制。这种设计增益控制范围为40 nm(1530~1570 nm),当输入功率在-40~-15 dBm的动态范围内,双激光增益控制的掺铒光纤放大器的平均增益和噪声系数分别约为22.22 dB和8.69 dB,而它们的漂移分别被钳制在0.69 dB和1.51 dB。系统性能测试表明:双激光控制掺饵光纤放大器在稳定性方面比单激光有着明显的优势。 相似文献
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Hirohisa Yokota Jun-ichi Igarashi Yoshitaka Satoda Satoru Ohuchi Yutaka Sasaki 《Optical Review》2002,9(3):94-99
A new all-fiber optical add-drop multiplexer (ADM) using a pair of fiber grating couplers (FGCs) was proposed and first demonstrated. It was theoretically and experimentally shown that both drop and add efficiencies could be maximized in the proposed ADM. It was also clarified that the crosstalk between dropped and added signals could be improved in the proposed ADM compared with that in the single FGC. Drop and add operations in the ADM for 3-channel WDM signals with 1.6 nm wavelength spacing were confirmed. The ADM with signal amplification ability, which consists of a pair of FGCs, an EDF, and a pump-LD, was proposed and demonstrated. It was confirmed that the dropped and transmitted optical signals could be amplified in the ADM, and would be able to expand fiber routing spans. 相似文献
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利用有限元法和传输矩阵法,对柚子型结构的光子晶体光纤啁啾光栅的反射谱进行了理论分析。得到了啁啾光栅参数和光纤参数对光子晶体光纤啁啾光栅反射谱的影响规律。结果表明随着啁啾系数和折变量的增加,光栅反射谱呈规律变化,当啁啾系数增大到一定程度时几个反射峰会连到一起,形成一个大的反射带宽。光纤的内包层直径和纤芯直径的改变能够影响各反射峰之间的间距。同时研究了切趾变迹对光子晶体光纤啁啾光栅反射谱的影响,研究表明,所用切趾函数会同时对多个峰进行切趾,每个峰的切趾效果都很好。对反射谱波动较大的几个峰相连的啁啾光栅经过柯西切趾后反射谱曲线平滑,适合于实际应用。 相似文献
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Abstract By controlling the cavity loss of the modes using a variable optical attenuator, specific intensities of distributed modes can be fed back into the erbium-doped fiber to produce signals without mode competition, thus resulting in stable lasing as a means to overcome mode competition in a homogenous gain medium. Two lasing signals were obtained with peak powers of approximately ?3.475 dBm and ?4.386 dBm for wavelengths of 1,540 nm and 1,548 nm, respectively, with a side mode suppression ratio of more than 43 dB. 相似文献
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用半导体激光器作调制器的双波长可调谐锁模光纤激光器 总被引:3,自引:2,他引:3
提出一种用法布里—珀罗腔半导体激光器(F—PLD)作调制器,用线性凋啾光栅(LCFG)进行波长选择的双波长环形腔主动锁模光纤激光器。利用线性凋啾光栅在腔内的色散效应使两个波长的光脉冲通过饵光纤(EDF)时在时域上分开,从而威小了不同波长的光脉冲同时通过饵光纤时造成的竞争,因此可以在室温下获得波长间隔较小的稳定的双波长光脉冲输出。实验中成功地获得了重复频率约为2GHz,波长间隔为0.92nm的稳定双波长光脉冲,并通过调谐线性凋啾光栅中心波长的位置使激光波长可以在约3nm范围内调谐。 相似文献
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Hai-Han Lu 《Optical Review》2002,9(1):29-32
This study proposed and demonstrated a directly modulated NTSC AM-VSB 77-channel plus Internet access system using a Fabry-Perot (FP) laser diode, an optical isolator, fiber Bragg grating (FBG), wavelength-division-multiplexing (WDM), channel conversion and two-way communication techniques over an existing multimode fiber (MMF) on the author’s campus. Performances of carrier-to-noise ratio (CNR) of >43dB composite second order (CSO) of >53dB and composite triple beat (CTB) of >53dB were obtained over a 2-km MMF transmission. The proposed two-way communication system is simple and suitable for fiber to the classrooms application. 相似文献
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双泵浦光子晶体光纤参量放大研究 总被引:1,自引:5,他引:1
利用光子晶体光纤在不同零色散波长附近具有不同色散的特性,研究了在零色散波长为780 nm和1550 nm附近的双泵浦光子晶体光纤参量放大过程.在780 nm附近,讨论了零色散波长变化对双泵浦光子晶体光纤参量放大的影响.数值模拟结果表明:当零色散波长发生微小的变化时,信号增益谱带宽会发生很大的变化.当两泵浦光之间的波长差值减小时,零色散波长的变化对参量放大的影响在很大程度上可以得到抑制,但是增益带宽会有一定的减小.依据这一原理,在1550 nm附近设计光子晶体光纤中的色散平坦光纤参量放大,在5 m长的光子晶体光纤中,当峰值功率为10 W时,得到了增益为65 dB,带宽达到420 nm且极为平坦的增益谱. 相似文献
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Shilie Zheng Xianmin Zhang 《International Journal of Infrared and Millimeter Waves》2005,26(7):1005-1016
A chirped fiber grating (CFG) written by the moving fiber/phase mask scanning beam technique with a uniform mask is used to demonstrate the dispersion compensation in the externally modulated microwave/millimeter-wave over fiber system. It is found that the use of the CFG is an efficient way to compensate for the severe RF power degradation induced by the fiber chromatic dispersion, which results in a significant improvement in the transmission performance. The signal to noise ratio is improved from 4.8 dB to 24.4 dB when 10.58 GHz RF signal carrying 5 Mbit/s QPSK format data is transmitted over 35 km single mode fiber. 相似文献