基于SOA全光波长变换的研究

利用Optisystem对基于半导体光放大器(SOA)全光波长变换进行模拟,找出了影响波长变换效率的因素.在成功模拟出波长变换的前提下,通过调整SOA的注入电流、半导体光放大器(SOA)腔长、泵浦波与信号波的频率差、泵浦波功率及耦合器衰减等参数的值,获得了最高变换效率为19.7dB的变换波.     

SOA全光波长转换技术及其研究进展

对基于半导体光放大器(SOA)全光波长转换技术的性能和特点进行了分析与比较.在此基础上,介绍了基于半导体光放大器(SOA)全光波长转换技术的最新改进方案和研究进展,并对其应用前景和发展方向进行了展望.     

Fast tunable wavelength conversion for all-optical packet switching

We demonstrate a simple scheme to achieve fast tunable wavelength conversion over a wide spectral range. The wavelength conversion is obtained by four-wave mixing in a semiconductor optical amplifier using a double-pump scheme, 2048-bit sequences at 2.5 Gb/s, incoming at a given wavelength, are alternatively converted toward two different wavelengths for a total conversion interval of 20 nm. With this method, the time needed to change the destination wavelength is much shorter than the bit duration. This feature makes any guard-time spacing between packets unnecessary. Bit-error-rate measurements show that the process occurs with negligible penalties (less than 0.3 dB).     

基于高非线性光纤和SOA非线性效应的星上再生波长变换

针对分布式卫星系统信息交换频繁、波长变换频 次高且由此导致信号损伤严重的特点, 提出了一种基于高非线性光纤(HNLF)和半导体光放大器(SOA)非线性效应的星上全光再生 波长变换方案。利用HNLF的自相位调制(SPM)效应对原始信号频谱进行展宽,通过 红移或蓝移滤波取出预变换信号,分别作为波长上变换或下变换的泵浦光信号,最后基于 SOA的四波混频(FWM)效应实现了对原始信号的波长变换。理论推导了波长变换方案的工 作原理,分析了波长变换性能与各结构参数之间的关系。仿真实验结果表明:本文方案在有 效 实现波长变换的同时能够一定程度地改善信号质量,Q因子改善 最高可达3dB以上,功率转换效率可达到20dB。     

一种基于SOA非线性效应的星上全光再生波长转换方案

为了解决分布式卫星光网络中频繁的信息交换和多跳转发导致信号损伤和信道拥塞严重的问题,提出了一种无需独立探测光源的再生波长转换方案。利用半导体光放大器(SOA)自相位调制(SPM)效应对光信号频谱进行展宽,再经偏移滤波后取出预变换信号;在此基础上,以预变换信号为探测光,通过SOA的四波混频(FWM)效应实现对原始信号的波长变换。研究结果表明,本文方案功率转换效率可达到23dB以上,当输入信号功率小于-23dBm时,输出信号Q因子改善超过3dB。     

一种新的四波混频全光波长变换实验研究

优化设计半导体光纤环形激光器产生波长连续可调谐窄线宽的激光输出,可调谐范围为４０ｎｍ。利用半导体光放大器的非线性效应四波混频,实现了码速为２．５Ｇｂｉｔ／ｓＳＤＨ信号光的波长变换,向上变换８．２４ｎｍ,向下变换１９．４９ｎｍ。在实验中不需要外加泵浦光源。     

A novel all-optical transport network with time-shared wavelength channels

High-speed and high-capacity transport networks are necessary for providing future broadband services and multimedia applications. Optical networks, such as wavelength-routed networks and optical switching networks, are the most popular solutions. However, the limited electronic switching capability constrains the scalability of the multihop wavelength routed networks, while the difficulty and complexity of implementing efficient optical buffers and optical contention resolution schemes constrains the development of optical switching networks. This paper proposes a new architecture for the optical transport networks based on time-wavelength-space routers (TWSRs). The TWSR is equipped without optical buffers and optical contention resolution devices. A connection is established by constructing a time-slot based lightpath (ts-lightpath) between source TWSR and destination TWSR. The paper also proposes a heuristic algorithm for the problem of establishing the set of efficient ts-lightpaths for a given set of connection requests. The effectiveness of the proposed network architecture with the heuristic algorithm is demonstrated by simulation.     

Cost-saving two-Layer wavelength conversion in optical switching network

A novel two-layer wavelength conversion (TLWC) scheme, for reducing the implementation cost of an optical switching (OS) node, is presented in this paper. The study stems from practical observation that wavelength converters are expensive. The paper thus presents a new OS node architecture that uses significantly less wavelength converters without compromising on drop performance. In this TLWC system, partial wavelength converters (PWCs), which can only convert wavelengths within a limited range, form the first layer; thereafter, complete wavelength converters (CWCs), which can convert wavelengths within all input ranges, form the second layer. When new optical data needs a wavelength converter, PWC resources are first provided; if PWC resources are not available, CWC resources are used. For the case of the CWC layer, a sharing-mode scheme called the share per fiber (SPF) mode for improving the utilization of the limited number of wavelength converters is proposed. Subsequently, a two-dimensional Markov-chain model of TLWC-SPF is presented to evaluate its performance. Numerical-simulation results are presented to verify the accuracy of the analytical model. The analysis shows that the cost of the OS fabric of TLWC-SPF is similar to an OS node employing a limited number of CWCs (i.e., CWC-SPF). However, in terms of wavelength-converter savings, the TLWC-SPF architecture provides 50% (in heavy load) savings compared to full wavelength conversion (FWC) optical nodes, while 40% savings is achieved compared against CWC-SPF nodes.     

40-Gb/s all-optical wavelength conversion based on a nonlinearoptical loop mirror

All-optical wavelength conversion based on a nonlinear optical loop mirror (NOLM) at 40 Gb/s is demonstrated for the first time. The effect of walkoff time between control beam and signal beams is investigated when the NOLM is used as an all-optical wavelength converter or an all-optical demultiplexer     

Dispersion monitoring in all-optical networks using wavelength conversion based on FWM

The first demonstration of chromatic dispersion monitoring in optical networks having employed all-optical wavelength conversion is described. Experimental results confirm that dispersion monitoring based on an in-band subcarrier tone combined with wavelength conversion based on four-wave mixing (FWM) render dispersion monitoring possible in an optical network utilising wavelength conversion     

基于交叉增益调制的全光波长转换实验研究

分析了半导体光放大器交叉增益调制的基本原理,并利用该机制进行了2．5Gbit/s的非归零码光脉冲的波长转换。向上波长转换间隔大于14nm。最后,对转换信号测量了接收机入纤功率和误码率的关系曲线、光眼图、消光比和光信噪比等参数,结果发现转换信号眼图清晰,张开度大,消光比大于10dB,光信噪比大于30dB。实验表明采用半导体光放大器的交叉增益调制可以较理想地实现2．5Gbit/s的非归零码的全光波长转换。     

基于全光波长变换和色散介质的可调谐光延迟线

对基于四波混频全光波长变换与色散介质组合的可调谐光延迟线进行了实验研究。将420m长的高非线性光纤(HNLF)分别与普通单模光纤(SMF)和色散补偿光纤(DCF)组合,依次实现了1ns和3ns的可调谐光延迟,实验结果与理论结果非常一致。     

基于非线性色散光纤的全光波长变换

理论推导了基于光纤中四波混频效应的全光波长变换效率公式,利用OptiSystem成功模拟出了基于非线性色散光纤的全光波长变换.通过调整抽运光与信号光的频率差、抽运光功率、光纤衰减系数、光纤的有效面积等参量,获得了变换效率为15.4dB的变换光.     

利用闲频光实现全光波长变换的研究

文章用OptiSystem模拟出了利用闲频光实现的全光波长变换.通过调整半导体光放大器(SOA)注入电流、SOA腔长、泵浦光与信号波的频率差、偏振、耦合器信号衰减与泵浦衰减等参数的值,获得了12 dB的变换效率.研究发现,利用闲频光实现的全光波长变换比利用变换光实现的全光波长变换有更好的稳定性.     

基于非线性光纤环镜的全光波长变换器性能分析

非线性光纤环镜是一种很有前途的全光波长变换装置。介绍了利用光束传输法（ＢＰＭ） 对耦合非线性薛定谔方程组进行数值解析,详细讨论了对变换信号质量起作用的因素,包括泵浦光脉冲与信号光脉冲之间的走离和初始时延、光纤长度、向长波长变换和向短波长变换等。结果表明,适当的初始时延可以补偿走离的影响,适当增加光纤长度可以改善脉冲波形。     

WDM-PON中一种基于波长选择开关的组播方案

方案使用幅度和相位正交调制的方式来承载单播和组播业务,利用波长选择开关对需要组播业务的ONU(光网络单元)和不需要组播业务的ONU进行分组,进而实现组播业务的传输.整个方案的控制策略完全集中在OLT(光线路终端)一端的WSS中,简化了组播控制的方法,使整个系统简单方便.     

一种新型基于光子晶体异质结耦合波导的全光开关的设计

基于电磁波在耦合波导中的传输特性,建立了一个光开关模型,利用耦合模理论、平面波展开法以及有限时域差分法进行设计和分析。分别分析改变介质柱的折射率和异质结位置变化对开关功能的影响。结果表明改变介电柱的折射率能影响开关的功能,而异质结耦合波导中介电柱的位置分布对光开关功能影响很小。利用这个特性可以在光开关的设计中有更多的灵活性。     

Lightpath Rerouting Algorithm to enhance blocking performance in all-optical WDM network without wavelength conversion

In this paper, we have proposed an efficient wavelength rerouting algorithm for dynamic provisioning of lightpath. In wavelength-division multiplexed (WDM) networks rerouting of lightpath can be used to improve throughput and to reduce blocking probability. We have proposed a Lightpath Rerouting Algorithm (LRRA) for dynamic traffic in WDM optical networks. The results have shown that LRRA can improve blocking performance of the network. In this paper, low complexity algorithm has been developed which is used for the calculation of blocking probability of network. The proposed algorithm has also been applied on the realistic network such as NSFnet for calculation and optimization of blocking probability of the network. The results have also shown that the proposed algorithm can be implemented to huge networks for good blocking performance of the network.     

A novel all-optical switch: the wavelength recognizing switch

A new class of an all-optical switch-the wavelength recognizing switch is proposed and experimentally demonstrated. The device uses a control signal to sense the wavelength of the input packet and taps a portion of the data packet to the appropriate output port. The device is based on noncollinear four-wave mixing in a broad-area traveling-wave semiconductor optical amplifier. Measured switching efficiency is +8.2 dB with -28.8 dB of crosstalk. The recognition bandwidth is as narrow as 0.03 /spl Aring/ and the 3-dB switching bandwidth is 42 nm.     

基于波长转换技术的一种低成本WDM-EPON方案

提出了一种新的波分复用以太网无源光网络(WDM-EPON)方案.该方案基于注入锁模和波长转换技术,可以重用现有EPON网络中的光网络单元(ONU),实现了由EPON向WDM-EPON的平滑升级.系统中,使用工作在注入锁定模式的FP激光器输出作为波长转换节点的输入探测光,显著降低了成本.仿真实验验证了这种低成本WDM-PON方案及其在升级应用中的可行性.