基于半导体光放大器和光滤波器的全光非归零码到归零码的转换

利用半导体光放大器模型和仿真软件对全光非归零码到归零码的变换进行了数值仿真.在仿真结果的基础上,实现了基于半导体光放大器和光滤波器的10 Gbps的全光非归零码到归零码的变换试验.试验结果显示在RZ码输入功率为－15 dBm时,该变换的误码率为1.0×10－9.     

利用单支半导体光放大器和光带通滤波器实现40Gbps归零码到非归零码的全光转换(英文)

为了解决全光码型转换中结构复杂和速率限制的问题,提出了应用于全光网络,利用半导体光放大器的非线性效应和光带通滤波器滤出特定光谱成分来实现全归零码到非归零码的全光转换方案.基于超快半导体光放大器模型,进行了40Gbps归零码到非归零码全光转换的仿真与实验验证.实验结果表明:40Gbps归零码到非归零码全光转换的功率损耗约为2dB,与仿真结果高度吻合,验证了该方案的可行性与有效性.     

基于半导体光放大器和受激布里渊散射的全光非归零码时钟提取

利用半导体光放大器(SOA)的增益饱和特性、自相位调制(SPM)效应和啁啾光纤光栅(CFBG)的滤波和啁啾特性共同作用实现了10 Gbit/s非归零码(NRZ)信号的时钟分量增强。经过该结构的非归零光谱的时钟分量增强后,其时钟数据抑制比提高了12.9 dB。时钟分量增强后的信号经基于受激布里渊效应(SBS)的时钟提取结构后实现了对非归零信号的全光时钟提取。这种新型非归零全光时钟提取结构具有对数据速率及数据格式透明,低抖动,不受码型效应的影响等优点。     

自启动的非归零/归零码和光电时钟信号发生器及码型转换

采用双波长注入一包含伪随机码发生器与相位调制器的光电振荡器可以同时得到非归零(NRZ)码,归零(RZ)码以及光,电时钟信号输出。该方案使用了光域耦合的双环路结构,在不增加有源器件的条件下实现边模抑制。相位调制器用于反馈调制并同时实现占空比可调的非归零码到归零码的转换。双波长的注入排除了编码信号在振荡器中引入的非时钟频率成分。实验给出了10 Gb/s工作速率下的结果,得到了抖动为637 fs的光信号输出。转换得到的归零码信号占空比约为33%。输出电时钟信号的相位噪声在频偏10 kHz处为-109 dBc/Hz,边模抑制比为58 dB。     

基于半导体光放大器和整形滤波器的40 Gb/s的归零正码波长变换研究

理论上分析了通过整形滤波器方法实现正码波长变换的原理,并讨论了滤波器带宽及偏移方向对正码脉冲效果的影响,解释了目前实验报道中多采用蓝移滤波方案的技术根由。在实验上利用半导体光放大器(SOA)和通带滤波器完成了40Gb/s的归零码波长变换实验,验证了理论分析的结构,证明了整形滤波器加半导体光放大器的方案可以实现正码的波长变换。这对于简化网络的设计,提高信号传输质量都有重要的意义。     

半导体光放大器环镜的非归零信号时钟分量提取

对基于半导体光放大器非线性环镜的非归零信号时钟分量提取进行了数值模拟和实验研究。不仅采用半导体光放大器的分段模型分别对简化方案和抽运一探测方案进行了2．5Gbit／s下的数值模拟，而且实验上采用这两种方案分别将2．5Gbit／s的非归零信号转换为包含其时钟分量的相应的伪归零信号。模拟计算结果与实验结果吻合得很好。实验和模拟结果均表明：采用简化方案时转换输出的伪归零信号所包含的时钟分量的强度小于采用抽运一探测方案的情况。10Gbit／s下的模拟计算结果表明在码型效应尚能容忍的前提下简化方案工作速率的上限小于抽运一探测方案。     

基于折叠式超快非线性干涉仪的全光码型转换理论和实验研究

码型转换是实现非归零(NRZ)信号全光时钟恢复的关键技术.提出了一种基于折叠式超快非线性干涉仪的全光NRZ到伪归零(PRZ)信号转换的新型方案.基于半导体光放大器的分段模型和超快非线性干涉仪的传输函数，建立了该方案的理论分析模型，数值模拟了不同速率下的码型转换过程.实验实现了稳定的10，20和40 Gbit/s的NRZ到PRZ信号的码型转换，分析了影响码型转换输出特性的因素，理论分析结果与实验结果基本符合. 关键词： 超快非线性干涉仪 半导体光放大器 全光码型转换     

一种全光逻辑或非门的理论和实验研究

基于单端半导体光放大器(SOA)中的交叉增益调制(XGM)效应实现了全光逻辑或非运算功能,建立了该方案的理论模型,进行了数值模拟.实验中实现了10 Gb/s的全光逻辑或非运算功能,并对理论模拟和实验结果进行了讨论和分析,指出了输出消光比与连续光功率及注入电流之间的关系.理论分析结果与实验结果相符合.     

一种新型多速率归零码全光帧时钟提取系统

提出了一种新型的、低成本的多速率归零(RZ)码全光帧时钟提取方案。采用低精细度的法布里-珀罗滤波器(F-P)直接提取不同速率的帧时钟,保证帧时钟的快速建立和快速消失。利用不同的偏振延时干涉仪(PDI)和低自由光谱区(FSR)的法布里-珀罗滤波器构成组合滤波器以实现多速率帧时钟提取。利用半导体光放大器(SOA)的自增益调制效应(SGM)对组合滤波器提取的帧时钟进行整形,降低帧时钟的幅度噪声和时间抖动。实验中,利用光开关切换不同的偏振延时干涉仪构成不同自由光谱区的组合滤波器实现了10 GHz、20 GHz和40 GHz的帧时钟提取,得到了高质量、低时间抖动的多速率帧时钟信号。     

10 and 20 Gb/s all-optical RZ to NRZ modulation format and wavelength converter based on nonlinear optical loop mirror

We present experimental and theoretical results on all-optical 10 and 20 Gb/s RZ to NRZ modulation format and wavelength converter based on a nonlinear optical loop mirror (NOLM). A vector model of converter was developed and the shape of converted pulses was found analytically for particular choice of polarization states. In the experiment, non-zero dispersion shifted fiber with a length 1200 m was used as a nonlinear medium. Pulses from a 10 GHz mode-locked semiconductor laser diode were modulated to form pseudorandom RZ signal and eventually time division multiplexed to 20 Gb/s. RZ pulses were subsequently converted to NRZ signal. The performance of the converter was evaluated experimentally using the data communication analyzer and bit error ratio tester.     

All-optical burst-mode clock extraction based on the thresholding operation of a modified terahertz optical asymmetric demultiplexer

To implement all-optical burst-mode clock extraction we adopt a modified terahertz optical asymmetric demultiplexer (MTOAD). The transmittance and reflectance of the MTOAD depend on the input intensity. For the MTOAD, two levels of pulse intensity can be chosen in such a way that while the pulses with similar intensity are reflected for both strong and weak pulses, only the strong pulse transmits. The device is useful, for example, for bit-level clock extraction from a packet, where strong and weak intensity pulses are assigned to ‘1' and ‘0', respectively. When the input optical signal power is fixed to −1.6 dBm and the intensity ratio between ‘1' and ‘0' is varied in the range of 0.2–0.5, the extinction ratio (ER) at the transmitted port is more than 10 dB and a clock amplitude jitter (CAJ) of the bit-level clock at the reflected port is less than 14%. Inversely, when the input power is varied in the range of −6–−1 dBm with fixed intensity ratio of 0.3, more than 11 dB of ER and less than 15% of CAJ are obtained.     

Simultaneous implementation of all-optical OR and AND logic gates for NRZ/RZ/CSRZ ON-OFF-keying signals

An all-optical scheme for simultaneously realizing OR and AND logic gates based on three-input four-wave mixing (FWM) arising in a single semiconductor optical amplifier (SOA) is proposed and demonstrated. It has the ability to process not only conventional non-return-to-zero-ON-OFF-keying (NRZ-OOK) and return-to-zero-OOK (RZ-OOK) formats but also carrier-suppressed return-to-zero-OOK (CSRZ-OOK) format signals. Firstly, the performance of 40 Gb/s logic operation is numerically evaluated by a comprehensive dynamic SOA model considering three input signal induced FWM effect. Then, 10 Gb/s experimental demonstrations with clear waveforms and high extinction ratios (ERs) further verify the logic integrity of this scheme. Thus, the OR and AND logic gates simultaneously achieved within a single logic unit is compact and cost-effective for future optical signal processing applications.     

基于半导体光放大器的非归零信号时钟恢复

提出了一种基于半导体光放大器加窄带光纤光栅滤波器,将非归零信号转换为伪归零信号,再把伪归零信号注入到主动锁模环行腔激光器进行时钟提取的非归零信号时钟恢复方案.利用该方案实现了10 Gb/s伪随机非归零信号的全光时钟恢复,对工作原理和结果进行了分析和讨论.实验证明该方案具有结构简单,调整容易,输出波形好的特点.     

All-optical logic AND-NOR gate with three inputs based on cross-gain modulation in a semiconductor optical amplifier

We report the realization of a novel all-optical logic AND-NOR gate based on cross-gain modulation (XGM). The used scheme requires only one SOA to perform the logic gate with three input signals. A 8.5 dB dynamic extinction ratio with a switching time of about 650 ps for the rise time and 100 ps for the fall time.     

A Novel All-optical Wavelength Converter Based on Self-pump Four-wave Mixing

A novel scheme of all-optical wavelength converter(AOWC) based on dual pump four-wave mixing(DP-FWM) was demonstrated. To suppress the ASE noise of the semiconductor optical amplifier (SOA), one of the two pumps was generated interiorly from a loop laser constructed mainly by tunable optical filter and SOA. The theoretical model and some experimental results were presented.     

A Novel All-optical Wavelength ConverterBased on Self-pump Four-wave Mixing

A novel scheme of all-optical wavelength converter(AOWC) based on dual pump four-wave mixing(DP-FWM) was demonstrated. To suppress the ASE noise of the semiconductor optical amplifier (SOA), one of the two pumps was generated interiorly from a loop laser constructed mainly by tunable optical filter and SOA. The theoretical model and some experimental results were presented.     

基于半导体光放大器平行双抽运对OFDM光信号进行全光波长变换性能研究

研究了基于半导体光放大器平行双抽运对光正交频分复用信号进行全光波长变换的系统.信号光源经2Gb/s电信号直接调制后再和双抽运光耦合,经半导体光放大器后,由于四波混频效应而产生新的波长的信号光.实验结果显示,经半导体光放大器四波混频效应后,产生新的波长的信号光将携带OFDM信号且偏振不敏感,转换效率与双抽运光之间的波长间隔,抽运与信号光波长间距,信号光与泵浦光之间的偏振夹角等有关.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.