【作者】 曹永盛；

【导师】 余重秀；

【作者基本信息】 北京邮电大学 ， 光学工程， 2010， 博士

【摘要】 随着互联网数据量与业务量的爆炸式增长,光通信已成为现代通信中的重要组成部分,其发展方向是大容量、高带宽的全光网(AON)。近年来,随着密集波分复用(DWDM)技术的广泛使用,光通信主干网的传输速度已可达到Tb／s量级。但作为光通信网络中不可缺少的一个部分——交换节点,仍需对数据进行光／电／光(O／E／O)转换和电域处理。由于电子交换与电信息处理速度已达到极限,这大大制约了现有通信网的传输速度,造成数据处理和传输的“电子瓶颈”。为解决这一问题,采用光电混合结构的光标记交换(OLS)技术,成为下一代光传输网(OTN)与光交换网(OSN)的发展方向。本论文对目前最前沿的两种光标记交换技术——正交调制光标记技术与光码(OC)标记技术的工作原理进行了理论研究,并通过仿真,对上述系统的参数设置与传输性能进行了分析比较；此外,通过理论研究与仿真分析,对基于自光电效应(SEE)的新型光控光交换器件——自电光效应器件(SEED)的工作特性与器件优化方案进行了研究。论文内容包括：1、正交调制光标记交换技术的研究搭建40 Gb/s ASK/FSK正交调制光标记交换系统的仿真模型：1)对正交调制光标记交换系统的结构、工作原理与传输性能进行了研究；2)对系统消光比(ER)、色散补偿方案与标记频率间隔等参数进行了优化,从而达到改善系统传输性能的目的；3)提出了一种利用光带通滤波器(OBPF)对FSK信号进行谱均衡的方法。仿真结果表明,利用该方案,可有效改善ASK净荷信号的接收质量；4)在网络核心节点处,提出了一种利用SOA-MZI结构对FSK光标记同时进行擦除与插入的方法。仿真结果表明,该方法可在功率代价很小的情况下,实现对FSK光标记的全光擦除与插入；5)引入两种先进调制方式——DPSK与DQPSK调制方式,通过对FSK、ASK、DPSK与DQPSK四种调制方式进行不同组合,提出40 Gb／s净荷下,DPSK/FSK、DPSK/ASK、ASK/DPSK、DQPSK/FSK与DQPSK/ASK共五种正交调制光标记交换系统。利用仿真软件,对上述系统搭建模型、分析系统性能、优化系统参数,并对不同调制方式与不同码型下的系统传输性能与抗噪性能进行了比较分析。结果表明,RZ-DQPSK/ASK标记交换系统可获得较高的标记传输速率、较高的接收灵敏度与较好的系统抗噪特性。2、相干探测光谱幅度码(SAC)标记交换系统的研究搭建40 Gb/s SAC标记交换系统仿真模型：1)利用光相干探测技术,对现有SAC标记识别单元进行了创造性改进：构建发射功率恒定,工作频率随时间线性变化的扫频本地振荡器(LO)。使用该LO对156 Mb／s,4波长SAC标记进行相干探测,并通过平衡检测法实现对标记的识别。利用该方法,可大大简化传统SAC标记识别单元,降低系统复杂度与成本,并可消除原有系统中过大的分光损耗；2)基于相干探测标记识别单元,利用仿真,对40 Gb／s多种净荷(IM、DPSK、DQPSK)下的SAC标记交换系统性能进行了验证,并通过比较分析,得知DQPSK净荷表现出了最佳的传输特性；3)提出了112 Gb／s,多信道、多速率、DQPSK净荷下的SAC标记交换系统,并利用仿真对其传输性能进行了验证；4)提出了一种由伪随机序列(PRBS)信号发生器和1-2光开关组成的新型SAC光标记编码器,并基于该编码器,首次对SAC标记的BER特性进行了测量；5)提出了相干探测隐式SAC标记系统,利用仿真,对625 Mb／s与1.25 Gb／s隐式SAC标记交换系统的性能进行了比较分析。结果表明,在该系统中,净荷速率不宜超过1.25 Gb／s,否则扫频LO将无法正确解出标记信号；6)提出了一种利用法布里-珀罗(F-P)可调滤波器与扫频激光器产生多频率SAC标记的方法。利用该方法,可减少标记发送单元中所需的激光器数量,简化系统结构,降低系统成本。在仿真验证中,使用单激光器可产生多达16个频率分量的SAC标记,并可将标记速率提高至1.25 Gb／s；7)基于标记栈原理,搭建相干探测多标记SAC交换系统。利用连续扫频LO,对40 Gb／s净荷下,携带256个标记的系统性能进行了验证。结果表明,净荷调制方式对标记接收质量影响很小。当标记数量由2个增加至64个时,标记质量下降幅度较大,但当标记数量由64个增加至256个时,标记质量只是略有下降。故使用标记栈路由可支持多标记系统正常工作；8)利用标记栈原理,提出了相干探测双节点SAC标记交换系统。通过搭建标记交换节点、标记处理单元与电控1×N光开关交换阵列,实现了可进行双节点交换、转发与传输的SAC标记交换网络。3、新型光控光交换器件——自电光效应器件(SEED)的研究在对量子限制斯塔克效应(QCSE)与SEED工作原理进行分析的基础上,利用等效电阻-电容(RC)模型、电压扩散表达式与基尔霍夫(Kirchoof)定律：1)对SEED光控光开关、对称SEED(S-SEED)光控光开关与S-SEED光控光缓存器进行了理论分析,并得出了上述三种器件交换时间随电压变化的近似解析式；2)根据理论分析结果与器件特性表达式,对上述三种器件的入射光功率、入射光波长与入射光强比等参数进行了优化,并通过仿真分析,得出了有效提高器件性能的方法；3)对基于SEED光控光器件的光标记交换系统进行了探索,尝试将基于SEED的光控光开关、光控光逻辑门与光控光缓存器应用于光标记交换系统的核心节点,期望可实现对光标记的全光处理及全光交换。更多还原

【Abstract】 Optical communication has become the one of the most important parts in modern communications, due to the explosive growth of Internet data and services,and its developing direction is all-optical network (AOS),with high-capacity and broad bandwidth. Recently, the transmitted data rate in backbone has reached Tb/s level, due to the wide application of dense wavelength division multiplexing (DWDM) technique.However, as an indispensable part in optical communication network, the switching node still needs optical/electronic/optical (O/E/O) transformation,and the packets need to be processed in electrical domain, which limits the transmission rate of the current communication networks and causes the "electronic bottleneck" on data processing and transmission, due to the limitations by the speed of electronic switching and electrical information processing.To resolve this problem, optical labeled switching (OLS) technique was proposed.OLS provides a mixed optoelectronic structure, and it has become the developing direction of next generation optical transport network (OTN) and optical switching network (OSN).The operation principles of two of the most promising optical labeled techniques---orthogonal modulated optical labeled technique and optical code (OC) labeled technique are theoretically studied, and the parameters setting and transmission characteristics analysis and comparison of these two techniques are investigated by simulation;furthermore, the operation principles and optimizing schemes of a novel optically controlled optical switching device based on self electro-optic effect (SEE)---self electro-optic effect device (SEED) are investigated by theoretic analysis and simulation.The contents include:1.Study on orthogonal modulated optical labeled techniqueBuilding the simulation setup of 40 Gb/s, ASK/FSK orthogonal modulated OLS system:1)the structure, operation principles and transmission performances of orthogonal modulated OLS system are studied; 2) to improve system transmission performance, some parameters, such as extinction ratio (ER),dispersion compensation scheme and label frequency spacing, are optimized;3) a novel method on FSK signal spectrum equalization by using an optical band-pass filter (OBPF) is proposed.According to the simulation results,the ASK payload signal quality can be improved by using this equalization method; 4) at the core node of network, a scenario on FSK optical label erasing and inserting by using SOA-MZI structure is proposed.Simulation results indicate that, by using this scheme, FSK label can be removed and inserted in optical domain, with low power penalty; 5) two advanced modulation formats---DPSK and DQPSK formats are introduced, and by combining four different modulation formats---FSK, ASK, DPSK and DQPSK, five orthogonal modulated optical labeled systems---DPSK/FSK, DPSK/ASK, ASK/DPSK, DQPSK/FSK and DQPSK/ASK systems, with 40 Gb/s payload signals, are proposed.Analysis on system performances and optimization on system parameters are accomplished by using simulation setup, and the system transmission performances and anti-noise performances of different modulation formats and code types are also investigated.The results revealed that at RZ-DQPSK/ASK system could reach a highest label bit rate,a best received sensitivity and an optimal transmission performance.2.Study on coherent detected spectral amplitude code (SAC) labeled switching systemBuilding the simulation setup of 40 Gb/s,SAC labeled switching system:1) by using optical coherent detection, some creative improvements and innovations on current SAC label recognition unit are achieved:a linear time-to-frequency swept local oscillator(LO)with a constant emission power is constructed.156 Mb/s,4-wavelength SAC labels could be detected by the LO, and recognized by balanced detection. This novel method significantly simplifies the conventional SAC label recognizing unit, reduces the cost and avoids the large optical splitting loss;2) based on the coherent detected label recognizing unit, SAC labeled system performances with 40 Gb/s, IM, DPSK and DQPSK payload signals are compared by simulation. The results reveal that DQPSK payload has the best transmission characteristic; 3) SAC labeled 112 Gb/s, multi-channel and multi-bit rate DQPSK system is proposed and demonstrated; 4) a novel SAC label encoder is proposed.It consists of pseudo-random binary sequence (PRBS) generators and 1x2 optical switches,and based on this encoder, the BER performance of SAC labels is estimated for the first time;5)based on coherent detection, SAC implicit labeled system is proposed,625 Mb/s and 1.25 Gb/s systems are demonstrated.The results imply that, in this system, payload bit rate can’t exceed 1.25 Gb/s, otherwise, frequency swept LO can’t detect the correct label signal;6) a novel method on generation of multi-frequency SAC labels,by using a Fabry-Perot (F-P) tunable filter and a frequency-swept laser, is proposed.The conventional system complexity and cost could be reduced by using this method, due to the number of lasers in label generator is decreased. SAC labels up to 16 frequencies could be generated by one laser, and the label bit rate can be accelerated to 1.25 Gb/s;7) based on label stacking principles and coherent detection, multi-label SAC switching system is proposed.By using continous frequency swept LO, systems with 40 Gb/s various payloads and 256 labels are demonstrated by simulation.The results indicate that label quality goes worse very quickly, when the number of labels from 2 to 64; however, label quality only has a slight change, when the number of labels from 64 to 256.That means multi-label system can be achieved by using label stacking; 8) by using label stacking principles, two-hop, coherent detected SAC labeled system is proposed.Label switching node, label processing unit and electrically controlled 1×N optical switches array are established. Therefore, a SAC labeled network with two-hop switching, forwarding and transmission is achieved.3.Study on a novel optically controlled optical switching component---self electro-optic effect device (SEED)Based on the analysis on quantum confined Stark effect (QCSE) and the operation principles of SEED, and by using an equivalent resistance-capacity (RC) model,voltage diffusion expressions and Kirchoof laws:1)theoretical analysis on SEED optically controlled optical switches,symmetrical-SEED (S-SEED) optically controlled optical switches and S-SEED optically controlled optical buffers is completed, and the approximate expressions, which reflect the relationship between the switch time and voltage of these three components are obtained; 2) some parameters of these components, such as input optical power, input optical wavelength and input power ratio are optimized, and some effective methods on enhancing the performances of the components are found by simulation analysis;3) exploration on an optical labeled switching system, which is based on SEEDs was studied. Attempting to applying SEED optically controlled optical switches, logic gates and buffers to the core node of the labeled switching system, and expecting the all optical label processing and switching can be achieved.更多还原