基于半导体光放大器瞬态交叉相位调制效应的高速反相和同相波长转换的研究

采用半导体光放大器(SOA)中的瞬态交叉相位调制效应是实现高速全光信号处理的有效途径.利用SOA和带宽为0.4 nm的窄带滤波器同时实现了重复频率为10 GHz、脉冲宽度为10 ps的同相和反相全光波长转换.当滤波器的中心波长相对于探测光载波波长蓝移0.25 nm或者红移0.05 nm时，得到反相波长转换；当滤波器的中心波长相对于探测光波长蓝移0.29 nm或者红移0.25 nm时，得到同相的波长转换.同时用数值模拟了从同相到反相波长转换的极性演化过程，理论分析和实验结果基本相符. 关键词： 半导体光放大器 波长转换 瞬态交叉相位调制     

基于同一结构实现全光逻辑“与门”和“或非门”的研究

提出了一种基于同一结构实现全光逻辑“与门”和“或非门”的新型方案，其理论基础是级联单端半导体光放大器(SOA)的交叉增益调制效应.利用单端SOA的动态理论模型成功地模拟了输入信号光为20Gb/s固定格式非归零信号时，该方案分别得到逻辑“与”和逻辑“或非”两种不同的输出结果.最后进行了实验验证，模拟结果和实验结果基本相符. 关键词： 半导体光放大器 交叉增益调制 全光逻辑     

新型全光逻辑与门的理论和实验研究

提出一种基于级联单端半导体光放大器（SOA）中交叉增益调制效应的新型全光逻辑与门， 建立了该方案的理论模型，数值模拟和实验实现了10Gb/s的全光逻辑与运算功能，分析了逻辑与运算结果与输入信号功率和消光比之间的关系，理论分析结果与实验结果相符合. 关键词： 半导体光放大器 交叉增益调制 全光逻辑与门     

半导体光放大器的光-光互作用及其应用

半导体光放大器（SOA）中的非线性系数约为普通光纤的10^9，为光子晶体光纤的10^7，而且有4种光-光互作用，即交叉增益调制（XGM）、交叉相位调制（XPM）、交叉偏振调制（XSM）及四波混频（FWM），可以灵活地组成各种光信号处理器件，如波长变换器、全光触发器、全光逻辑、全光时钟恢复、全光缓存器……等，正成为整个光信号处理的基础。文章介绍了它们的原理和简单应用。     

100Gb/s归零码信号的2R再生

本文提出了基于半导体光放大器(SOA)中的瞬态交叉相位调制(T-XPM)效应与交叉增益压缩(XGC)效应的全光2R再生方法, 同时研究了SOA中的T-XPM效应获得反逻辑码信号以及XGC 效应光开关门的特性, 实现了100 Gb/s归零码(RZ)信号的2R再生, 接收机灵敏度提高了1.7-2 dB; 对该方案中的反逻辑码对于再生效果的影响进行了量化研究, 并在C波段范围内研究了该再生方案的再生效果, 实现了覆盖1535-1555 nm的全光2R再生.     

利用半导体光放大器实现10 Gb/s全光半减器的组合逻辑实验研究

提出了一种新型全光半减器组合逻辑方案.该方案基于两个半导体光放大器(SOA)和窄带光滤波器(NOBPF).利用SOA的四波混频(FWM)和交叉增益调制(XGM)效应,通过调整NOBPF的中心波长,第一个SOA产生逻辑"A·B"门,提供半减器的"借位",同时该SOA产生"同或"逻辑;第二个SOA产生"非"逻辑,两个SOA级联后产生逻辑"异或"门,提供半减器的"差"位.实验中,实现了两路10 Gb/s伪随机归零(RZ)码信号间的全光半减逻辑运算.     

基于SOA的环形腔激光器在全光信号处理中的应用

半导体光放大器（SOA）因其具有良好的光光互作用特性,包括交叉增益调制、交叉相位调制、交叉偏振调制以及四波混频等,在全光信号处理技术中已经获得了广泛的应用。利用SOA与光纤反馈可构成环形腔激光器S_FRL。在S—FRL中将SOA的光一光互作用特性与反馈条件相结合,可以改变孓FRI．的起振、抑制、选频等多种状态,从而构成不同功能的全光信号处理器件。在分析S—FRL激光振荡原理的基础上,提出了双环耦合的S-FRL,并以此为基础构成一种双环耦合的双稳态触发器,进而构成一种同步脉冲展宽器;还提出了一种级联的S-FRL,由此构成一种基于负逻辑的全光判决器。     

基于SOA交叉增益调制效应的全光组合逻辑

基于半导体光放大器(SOA)的交叉增益调制效应(XGM),提出了几种由基本逻辑与门构成的全光组合逻辑,包括一位比较器、带控制端口的2线-1线优先编码器、2线-4线译码器、2选1选择器,介绍了它们的基本结构、工作原理和真值表.利用扩展端口可进行多个组合逻辑级联,从而实现多端口、多位全光组合逻辑,如两个2线-1线优先编码器级联可实现4线-2线信号编码.结果表明基于SOA的XGM实现全光组合逻辑,原理简单、响应速度快、易于实现,是未来光子集成的一个重要发展内容.     

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.     

基于双半导体光放大器的读/写分别控制的新型全光缓存器

全光缓存器能够在光域内对数据包进行缓存,解决数据包在节点的冲突。提出了一种新型可擦写的全光缓存器,该缓存器以半导体光放大器(SOA)为非线性相移器件,利用信号光和控制光在半导体光放大器中的交叉相位调制实现信号在光域内的"写入"和"读出"。在注入信号峰值功率相同的条件下,双半导体光放大器结构的采用还可以对信号光实现功率补偿,比利用单个半导体光放大器进行"写入/读出"控制延长了缓存时间,并能有效克服在数据包"写入"缓存器时造成的输出端口处信号光的泄漏。该缓存器顺利实现了2.5 Gb/s数据包的多圈缓存。     

Effect of amplified spontaneous emission on semiconductor optical amplifier based all-optical logic

The performances of all-optical logic gates XOR, AND, OR, NOR and NAND based on semiconductor optical amplifier (SOA) have been simulated including the effects of amplified spontaneous emission (ASE). For the parameters used, all-optical logic gates using SOA are capable of operating at speed of 80 Gb/s.     

Optical nonlinearities in semiconductor optical amplifier and electro-absorption modulator: their applications to all-optical regeneration

Semiconductors have large optical nonlinearity with response speed in the several tens of picosecond range, making them ideal use as all-optical regenerators and wavelength converters. We theoretically and experimentally investigated optical nonlinearities induced by carrier dynamics both in forward biased semiconductor waveguide (SOA) and in reverse biased semiconductor waveguide (EAM). We made a detailed theoretical study of carrier dynamics in semiconductor waveguides by using the newly developed time-dependent transfer matrix method. To confirm the simulation results, we propose utilizing a polarization discriminating delayed interferometer (PD-DI) configuration as a simple technique for measuring optical nonlinearities such as cross gain modulation (XGM), cross absorption modulation (XAM), and cross phase modulation (XPM). In the first part of the paper, we reviewed SOA-based regenerators. As expected from the simulation results, we confirmed that injection of the transparent assist light was very effective in reducing of the SOA gain recovery time of down to a few tens of picoseconds. We further demonstrated 40 Gbit/s regeneration using an SOA-one-arm MZI (so-called UNI) configuration. The superior regeneration capability of two-stage UNI was successfully confirmed by a recirculating loop experiment up to 30,000 km with 150 regenerations. In the latter part of the paper, we reviewed all-optical regenerators using EAM. A bit-synchronized rf-driven XAM 3R regenerator consisting of only one EAM for both gating and timing correction was demonstrated at 20 Gbit/s. An EAM in conjunction with delayed interferometer configuration, which utilizes XPM as well as XAM in the EAM, has structurral simplicity and fast regeneration operability up to 100 Gbit/s. The fast response of EAM allows the optical regeneration with a small pattern word effect.     

Analytical and simulative studies on optical NOR and controlled NOR logic gates with semiconductor optical amplifier

Semiconductor optical amplifier (SOA) is used for different successful frequency based switching operations. In this paper the authors describe the simulation study of the performances of SOA in various optical switches like frequency conversion, add-drop multiplexer and frequency encoded optical NOR gate, which is one the most important gates in logic family as it is known as one of the universal logic gates. Again, the controlled optical NOR logic operation with semiconductor optical amplifier is also proposed in this paper.     

基于半导体光放大器的环路型全光缓存器中功率均衡的新方法

全光缓存器能够在光域内对数据包进行存储而不需经过光电光的变换,成为全光网的重要组成部分,其性能的优劣将直接影响到网络的丢包率等。但在半导体光放大器中交叉增益调制和交叉相位调制效应并存,导致基于半导体光放大器的环路型全光缓存器中缓存后输出的数据包与未缓存数据包的输出功率间存在不均衡,使得网络误码率增加。在详细分析全光缓存器工作原理的基础上,利用半导体光放大器中交叉增益调制和交叉相位调制并存的现象,巧妙地提出了将控制脉冲反相并配合电可调衰减器的新方法。该方法简单易行,有效解决了此类全光缓存器中数据包输出功率不均衡的难题,缓存器性能得到了极大改善。此方法适用于所有基于半导体光放大器的环路型全光缓存器。     

All-optical XNOR and AND gates simultaneously realized in a single semiconductor optical amplifier with improved dynamics

All-optical XNOR and AND logic gates using four-wave mixing (FWM) and cross-gain modulation (XGM) in a single semiconductor optical amplifier (SOA) with improved dynamics are simultaneously realized. By numerical simulation, the effects of the input optical wave powers and injection current on the critical factors of the logic gate performances, such as the ON--OFF contrast ratio, the power-output level of the logic `1', and the difference between power outputs of the logic `1', are investigated in detail. In addition, the effect of the counter-propagating CW pump on the gain recovery is analysed.     

A novel frequency encoded all optical logic gates exploiting polarization insesensitive four wave mixing in semiconductor optical amplifier, filtering property of ADD/DROP multiplexer and non-linearity of reflective semiconductor amplifier

All optical logic gates exploiting polarization independent four wave mixing in semiconductor optical amplifier (SOA), filtering property of ADD/DROP multiplexer (ADM) and non-linearity in reflective semiconductor optical amplifier (RSOA) have been proposed. The logic gates proposed are polarization independent which ensures hardware simplicity and greater speed. The all optical frequency encoded logic gates NOT, OR, NOR, AND, NAND, X-OR, X-NOR are implemented which are very useful in optical computing ad signal processing, cryptography, etc. The logic gates proposed have the advantages that there is no intensity loss dependent problem, and are polarization and temperature insensitive.     

Modeling of semiconductor optical amplifier RIN and phase noise for optical PSK systems

Phase modulation schemes are attracting much interest for use in ultra-fast optical communication systems because they are much less sensitive to fibre nonlinearities compared to conventional intensity modulation formats. Semiconductor optical amplifiers (SOAs) can be used to amplify and process phase modulated signals, but with a consequent addition of nonlinear phase noise (NLPN). Existing SOA NLPN models are simplistic. In this paper we show that a more accurate model can be used, which results in simple expressions for SOA nonlinear noise, in particular when used to amplify differential phase shift keyed modulated data. The model is used to calculate the optical signal to noise ratio introduced by a power booster SOA and the first inline amplifier of a 40 Gb/s NRZ-DQPSK single channel link.

     

基于SOA全光偏振调制的双信道光传输系统的仿真与分析

仿真并分析了基于半导体光放大器全光偏振调制的双信道光传输系统模型.该系统分别利用两级半导体光放大器的交叉偏振调制效应(XPolM),将两路独立的强度调制的抽运光变换到一路探测光的两个正交的偏振态上,实现双通道偏振复用的全光数据传输.首先对单个半导体光放大器的动力学过程进行了理论分析,数值计算了具有不同抽运光功率的半导体光放大器对探测光偏振态的影响,进而对双半导体光放大器偏振复用系统的调制/解调原理进行了分析,模拟仿真了双半导体光放大器的双通路偏振复用的调制及解调过程,仿真结果与实验结果相符.