基于高非线性光纤中四波混频效应的全光取样系统

为了克服高比特率光信号实时取样时所面临的高速模数转换(ADC)限制,构建了一套基于高非线性光纤(HNLF)中四波混频效应的全光等效取样系统。全光取样系统主要包括取样脉冲信号产生、全光取样门和信号处理3部分,其中全光取样门为本系统的核心部分。取样脉冲和信号共同注入到HNLF中,基于四波混频效应实现全光取样。实验中,分别以10Gb/s、40Gb/s非归零OOK信号进行了取样实验验证。实验结果表明该取样系统可以实现高速光信号的取样过程。本文取样系统结构简单,且不受光信号速率的限制,可应用于更高速率的信号测量。     

基于HNLF的全光二进制相位编码微波信号调制研究

在高度非线性光纤中,基于交叉极化调制效应提出了一种新的全光方案,生成一个二进制相位编码的微波信号,该信号载波频率可以广泛调谐。通过实验生成了载波频率20GHz时编码率为5Gb/s、载波频率30GHz时编码率为7.5Gb/s的两个二进制相位编码的微波信号。最后对该系统的脉冲压缩能力进行了评估,测量结果与理论分析相符。     

基于光相位信号延时自相干的相位信息高速实时取样系统

提出了一种基于光相位信号自相干的高速光相位实时取样方案。利用时延为10ps的延时干涉仪(DI),将待测光信号的相位信息转换为强度信息;再在高非线性光纤(HNLF)中,利用四波混频(FWM)效应对强度信号进行取样。在接收端,利用不同中心波长的光滤波器(OBPF)即可滤出不同时间点的取样信号,从而在光域同时完成高速光相位信息的实时取样和取样信号的串-并转换。本文方案具有成本低、对测信号码率和波长不敏感的优点。实验中,对9GHz正弦调制以及10Gb/s非归零码调制的光相位信号实现了100G/s的高速实时取样系统,并转换为10路10G/s取样信号输出,最终恢复取样光信号的相位波形。     

高非线性微结构光纤环镜开关效应的实验研究

利用基于高非线性微结构光纤的非线性光纤环镜,在10Gb/s光传输系统中进行了全光开关的实验研究.利用中心波长在1550nm的皮秒脉冲激光器,在以25m长微结构光纤作为非线性介质构成的光环镜中,实现了非线性相移为π的开关操作,同时还发现这种全光开关具有脉冲整形的功能.     

利用微结构光纤进行全光再生的实验研究

利用自相位调制(SPM)效应和窄带滤波器,在高非线性微结构光纤(MF)中实现了全光2R再生,获得了无波长变换的再生信号。实验中,再生前的信号由经过一段普通单模光纤(SMF)和衰减器的10Gb/s脉冲信号获得,两段MF的非线性系数均为36W-1·km-1。通过两级2R再生后,获得了与初波长相同的再生信号,再生效果良好。实验结果表明,高非线性MF在全光再生方面有很大的应用潜力。     

卷积码在光正交频分复用系统中的应用

将卷积码成功地应用到直接检测的光正交频分复用(OFDM)光纤传输实验系统。实验中,产生了2 Gb/s的QPSK OFDM编码光信号,并成功地在标准单模光纤中传输了200 km,和没有采用卷积码的相比,系统的误码性能获得明显提高。在误码率10-3时,可节省1 dBm左右的光功率。实验结果表明,卷积码可应用到OFDM系统。     

差分相移键控的非归零到归零格式转换研究

提出了一种全新的基于相位-强度混合调制和色散补偿的光差分相移键控(DPSK)信号的非归零(NRZ)到归零(RZ)格式转换器,理论分析了转换器参数对转换的影响,数值研究了恶化条件下的10 Gb/s的NRZ-DPSK到RZ-DPSK的格式转换。实验展示了10 Gb/s的DPSK信号格式转换及解调后的误码性能。计算结果表明,通过设计转换器参数可获得低占空比RZ-DPSK信号,且转换后信号质量较高。实验结果表明格式转换功率代价较低,转换后RZ-DPSK信号时间抖动较原NRZ-DPSK信号减小。该格式转换器还适合光四相差分相移键控(DQPSK)的非归零到归零格式转换及多波长操作。     

双二进制调制在高速LiNbO3光调制器上的实验实现

通过实验方式在LiNbO3光调制器上实现了比特率为11.3 Gb/s的光信号的双二进制调制格式,测试并分析了相关的实验参数,包括调制前后的电眼图、光眼图,以及经过长距离光纤传输后的性能编号及比较等.实验证明,经过双二进制调制后的光信号经过长距离传输后较未调制的光信号眼图具有明显的改善.     

基于光纤光参量放大的多通道全光非归零/归零码转换器

提出了一种基于光纤光参量放大器(FOPA)的多通道全光非归零码(NRZ)/归零码(RZ)调制格式转换的方案.该方案中,非归零码信号与同步的时钟抽运光共同注入到高非线性光纤(HNLF)中,由高非线性光纤构成的参量放大器把非归零码信号转换为归零码信号,同时不改变信号光的波长.多通道的码型转换器以两路10 Gb/s的非归零码进行了实验论证.转换后的归零码信号的信噪比(SNR)高于7.6 dB,其脉冲宽度约为30 ps,并且具有3dB的消光比(ER)提高.根据多通道码型转换器的实现原理,该码型转换器可以应用于40 Gb/s或更高比特率的多通道码型变换操作.     

基于半导体光放大器的四波混频效应对正交频分复用光信号进行全光波长变换

实验研究了基于半导体光放大器(SOA)的四波混频(FWM)效应的单抽运光正交频分复用(OFDM)信号的波长变换系统.信号光源和抽运光源分别由两个不同输出波长的可调分布反馈式激光器(DFB-LD)产生.信号光源经2.5 Gb/s OFDM的电信号直接调制后再和抽运光源耦合,经光放大器后在SOA实现波长变换.实验结果显示,耦合信号经SOA四波混频效应后,产生新波长的信号光将携带OFDM信号,且转换效率与信号光和抽运光的功率、波长以及两者的偏振夹角有关.同时也测量了转换的OFDM信号的功率-误码曲线和接收星座图.     

A novel self-surviving architecture for next-generation OFDM passive optical network supporting colorless ONUs

In this paper, we propose a novel self-surviving architecture for next-generation orthogonal frequency division multiplexing (OFDM) passive optical network (PON) supporting colorless optical network units. The proposed scheme can protect distribution and feeder fiber simultaneously. Two different frequency bands are used in this proposed system for paratactic OFDM-PON. The disrupt signals can be restored via the fiber links of the neighboring OFDM-PON without special protecting fibers. We analytically and experimentally study the receiver sensitivity to downstream 10 Gb/s OFDM signals and upstream 2.5 Gb/s NRZ signals. The proposed architecture is designed mainly for next-generation PON systems.     

DCF色散补偿性能的研究

分析了光纤色散和非线性效应。研究了利用色散补偿光纤(DCF)进行色散补偿的三种方案,数值模拟了采用这三种方案对在G.652光纤上传输375 km速率为10 Gb/s和40 Gb/s光信号进行色散补偿时入纤光功率对系统误码性能的影响,并分析了模拟结果,筛选出其中一种最好的方案,给出了具体的入纤光功率的取值范围。     

Multi-wavelength conversion at 10 Gb/s and 40 GHz based on nonlinear effects in HNLF

We present experimental results and numerical simulations of multiple-wavelength conversion of 10 Gb/s non-return-to-zero (NRZ) signals based on 2-pumps four-wave mixing and of 40Gb/s return-to-zero (RZ) signals through supercontinuum (SC) generation in a highly nonlinear fiber (HNLF). Two pumps with a 100 GHz separation located in the region of anomalous dispersion of the HNLF were combined to form a beat signal The 10 Gb/s NRZ signal anchored on ITU grid was converted with gain into 6 new signals and 6 idlers with 100 GHz separation. High quality sc with bandwidth exceeding 50 nm was generated when the HNLF was pumped with 25 dBm average power. Sliced sc can be used as a source for all-optical multicasting.     

Finely tunable wavelength conversion of high bit-rate signals byusing a superstructure-grating distributed Bragg reflector laser

Finely tunable wavelength conversion of high bit-rate signals is analyzed numerically and demonstrated experimentally-to a wavelength range from 1530 to 1560 nm-by using a superstructure-grating distributed Bragg reflector laser. Transmission of a 10 Gb/s converted signals over a 100 km-long optical fiber is also demonstrated using a dispersion-shifted optical fiber     

System performance evaluation of the FSA submarine opticalamplifier system

The FSA submarine optical amplifier system developed for commercial use is designed to transmit 2.5 and 10 Gb/s signals flexibly; its repeater spacing is 90 km. It contains six line pairs to yield a maximum transmission capacity of 60 Gb/s. Its system configuration, and the characteristics of its fibers and optical amplifiers, which realize effective dispersion and optical passband management, are introduced. We discuss its performance with regard to the parameters significant in optically amplified transmission: evolution of zero dispersion wavelength (ZDW), polarization mode dispersion (PMD), and fiber nonlinearity induced impairments. Signal-to-noise ratios (SNR's) for 2.5 and 10 Gb/s signal transmission are measured and the improvements offered by polarization scrambling are also discussed. Finally, ZDW, PMD, and SNR characteristics of the system after installation are reported     

Design and performance of an optical path cross-connect systembased on wavelength path concept

This paper describes the system design and performance of an optical path cross-connect (OPXC) system based on wavelength path concept. The (OPXC) is designed to offer 16 sets of input and output fiber ports with each fiber transporting eight multiwavelength signals for optical paths. Each optical path has a capacity of 2.5 Gb/s. Consequently, the total system throughput is 8×16×2.5=320 Gb/s and the OPXC features high modularity and expandability for switch components. By exploiting planar lightwave circuit (PLC) technologies, four sets of (8×16) delivery-and-coupling-type optical switches (DC-switches) are developed for the 320 Gb/s throughput OPXC system. The DC-switch offers the average insertion-loss of 12.6 dB and ON/OFF ratio of 42.1 dB. The PLC arrayed-waveguide gratings are confirmed to successfully demultiplex the eight directly modulated signals, multiplexed at a spacing of 1 nm, with a crosstalk of under -25 dB. Eight wavelength-division multiplexing signals, directly modulated at 2.5 Gb/s, are confirmed to be transported over 330 km via a cross-connection node in the test-bed system that simulates five-node network. The experimental performances demonstrated In this paper ensures full scale implementation of the proposed optical path cross-connect system with 320 Gb/s throughput and high integrity     

10-Gb/s optical transmission up to 253 km via standard single-modefiber using the method of dispersion-supported transmission

Using the new method of dispersion-supported transmission, 10 Gb/s signals at 1.53 μm wavelength are transmitted on standard single-mode fiber with zero dispersion at 1.3 μm via the record length of 253 km without in-line regeneration. Detailed experiments with a directly modulated laser demonstrate the system performance for different fiber lengths ranging from 0 up to 253 km     

160×10Gbs C+L波段3040km无电再生光传输系统的研究与实现

大容量超长距离(ULH)传输是一种非常有应用前景的技术,本文介绍160×10GbsC+L波段3040km实际光纤的无电再生光传输系统的研究和实现.系统波道间隔为50GHz,波道速率10.7Gbs,发送采用CSRZ码,具有超强FEC功能,光信噪比大于15dB.国内首次成功在实际光纤传输3040km的C+L波段10Gbs信号,首次将C+L宽带喇曼光纤放大器应用于ULH系统,连续24小时无误码.取得的有实际意义的试验成果为我国的ULH系统的应用,提供了系统的性能、指标、参数、标准等实验依据.     

All-optical wavelength conversion by semiconductor opticalamplifiers

Following a brief introduction to the applications for wavelength conversion and the different available conversion techniques, the paper gives an in depth analysis of cross gain and cross phase wavelength conversion in semiconductor optical amplifiers. The influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. This can be overcome using cross phase modulation in semiconductor optical amplifiers that are integrated into interferometric structures. The first results for monolithic integrated interferometric wavelength converters are reviewed, and the quality of the converted signals is demonstrated by transmission of 10 Gb/s converted signals over 60 km of nondispersion shifted single mode fiber     

基于MIMO构架的光OFDM系统研究

文章在分析无线正交频分复用(OFDM)技术和单模光纤偏振特性的基础上,研究了一种基于多输入多输出(MIMO)框架的光OFDM系统并搭建了实验平台.系统将两路12 Gb/sOFDM信号通过偏振复用为24 Gb/s信号,实现了两路信号的解调输出.实验证明,该系统可扩展光纤信道中的频谱划分,增大信道容量,具有较强的对抗光纤色散的能力.