基于单端SOA波长转换器的消光比特性分析

对一种基于单端半导体光放大器(SOA)的交叉增益调制型(XGM)全光波长转换器结构建立了动态理论模型,以这个模型为基础分析了抽运光功率、探测光功率、剩余反射率、转换波长转换间隔、注入电流对转换后探测光的输出消光比的影响.结果表明,利用单端SOA实现波长转换比普通SOA实现波长转换将获得更好的输出消光比特性.     

增益调制型波长转换器消光比均衡的研究

利用半导体光放大器 (SOA)中交叉增益调制 (XGM)效应成功地实现了 62 2 Mb/ s和 2 .5Gb/ s信号的波长转换。对波长上 /下转换性能的研究表明 ,使用增益峰值波长比信号波长长的SOA可以有效地实现上 /下转换效率和消光比均衡 ,从而使这种类型的波长转换器在波分复用器(WDM)全光网中获得更大的应用     

基于SOA中XGM效应全光超宽带高斯单边信号源的研究

提出了一种基于半导体光放大器（SOA）中交叉增益调制（XGM）效应产生高斯单边信号（monocycle）脉冲的方案。该方案只需要单个外部光源和单个SOA,结构简单;采用相向的工作方式可以改善输出信号的消光比;输出的monocycle信号光只含有一个波长,在光纤传输过程中上下脉冲不会引入时间差。利用Optisystern...     

基于并联SOA的全光广播式超宽带脉冲形状调制技术

基于半导体光放大器(SOA)中交叉增益调制(XGM)效应,采用SOA的并联结构,提出了一种全光产生广播式超宽带(UWB)脉冲形状调制(PSM)信号的方案。该方案同时产生三路超宽带PSM信号,具有多用户传输数据的能力,可为多址通信作理论基础;采用相向的工作方式可以改善输出信号的消光比。利用OptiSystem7.0软件对方案进行仿真,分析了输入信号脉冲宽度、输入光功率和波长对产生的超宽带PSM信号的影响,对信号的传输特性进行了研究。结果表明,本文方案对输入信号脉冲宽度和输入光波长具有良好的容忍度,并且给出了输入光功率的优化范围。     

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。     

波分复用-光时分复用波长转换信号的消光比研究

对基于半导体光放大器(SOA)交叉增益调制(XGM)效应的全光波分复用一光时分复用(WDM—OTDM)转换后的两路时分复用输出信号的消光比(ER)特性进行了分析。研究了两路波分复用的输入抽运光和探测光的功率、波长、抽运光的消光比、数据速率以及半导体光放大器的偏置电流、腔长和模场限制因子对转换信号消光比的影响。模拟结果表明，增大抽运光输入功率，选择长波长抽运光，可以增加转换光相应信道消光比，但减小了相邻信道的输出消光比；增加抽运光消光比，可以提高转换光消光比，但各个信道增长幅度不同；减小探测光输入功率，选取短波长探测光波长，增加半导体光放大器的腔长和模场限制因子以及大的偏置电流可提高转换光消光比；对于两路或多路波分复用信号转换时分复用信号的过程中，一定要考虑转换光每个信道消光比的均衡。     

基于XGM的SOA波长变换器噪声特性分析及实验研究

本文将半导体光放大器的ASE噪声功率引入到SOA分段动态模型,得到随SOA长度变化的ASE噪声功率,并讨论了偏置电流、泵浦光功率、SOA长度对变换性能影响.理论计算结果表明,大的偏置电流有利于提高消光比(ER)和信噪比(SNR);对于长度一定的SOA和一定的偏置电流,泵浦光功率存在最佳值;SOA长度存在信噪比最佳值.我们对2.5Gbit/s SDH信号进行了XGM方式波长变换,实验结果与理论分析一致.     

基于半导体光放大器的组播实验研究

提出了一种基于半导体光放大器(SOA)的组播实验方案,首先利用谱展宽和谱切片得到多波长脉冲源,将其作为探测光并与信号光共同注入到SOA中,利用SOA的交叉增益调制(XGM)效应,信号光与每一个波长的脉冲光发生作用,在SOA输出端通过可调光带通滤波器(TBDF)得到每一波长的变换后信号,实现光信号的组播过程。在实验中,10 Gb/s的归零(RZ)码作为信号光,而由多波长脉冲源产生的4波长脉冲光作为探测光,在探测光波长附近分别得到了与编码信号光逻辑取"非"的信号。     

基于SOA-XGM波长转换器消光比特性的研究

建立了基于半导体光放大器交叉增益调制(SOA XGM)的波长转换理论模型,利用分段方法对XGM波长转换器同向和相向两种工作方式下消光比特性作了详细的研究。结果表明,相同情况下相向工作方式下的输出消光比特性要优于同向工作方式的。最后,从物理上对两种工作方式消光比和噪声特性的差异做了解释。     

基于SOA互增益调制双折射效应的全光2-4电平编码转换

提出了一种利用半导体光放大器(SOA)的互增益调制(XGM)的双折射效应实现全光2-4电平编码转换的方法.两路2-电平强度调制光信号正交偏振合波后,沿SOA的主轴进入,利用SOA的偏振调制实现被调制信号光的偏振调制,通过检偏输出4-电平强度调制光,从而实现2-4电平调制的编码转换.     

增益调制型波长转换中信号光波长的选择

增益调制型波长转换中 ,为得到转换后信号最大的消光比 (ER) ,信号光波长应该比半导体光放大器 (SOA)的小信号增益峰值波长长。采用分段模型 ,考虑了SOA中增益谱的不对称性以及增益峰值波长随载流子密度的漂移 ,深入研究了信号光功率 ,ER ,参考光功率 ,波长以及SOA注入电流对选择信号光波长λpk ,s 以及消光比改善量的影响。模拟计算表明 ,信号光功率每增加 3dB ,λpk ,s 就需向长波长移动约 7nm。信号光ER增加、参考光功率增加以及SOA注入电流的增加 ,λpk ,s 需向短波长移动。消光比改善量随信号光功率和电流的增加而显著增加 ,随信号ER的增加而降低 ,但是参考光功率和波长变化时影响不大     

40 Gbit/s wavelength conversion in cascade of SOA and NOLM and demonstration of extinction ratio improvement

The authors demonstrate that the extinction ratio (ER) can be improved when a nonlinear optical loop mirror (NOLM) is used as a wavelength conversion medium. At 4O Gbit/s. An extinction ratio (ER) of 7 dB for a converted signal generated by cross-gain modulation in a semiconductor optical amplifier is improved to an ER of 10 dB after wavelength conversion in an NOLM.     

基于半导体光放大器-交叉增益调制波长转换器消光比特性的研究

建立了基于半导体光放大器一交叉增益调制(SOA-XGM)的波长转换理论模型，利用分段方法对交叉增益调制波长转换器同向和相向两种工作方式下消光比(ER)特性作了详细的研究。结果表明，波长转换器的输出消光比随转换速率增加而减小，而且转换速率越高，减小得越快；随着抽运波长的变化，消光比有一个对应于峰值增益波长的最佳抽运波长；波长向下转换(Δλ＜0)时的消光比要明显优于向上转换(Δλ＞0)；输出消光比也随着输入消光比的增大而增大。相同情况下相向工作方式时的输出消光比特性要优于同向工作方式。最后，从物理上对两种工作方式消光比和噪声特性的差异作了解释。     

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.     

Broad-range tunable wavelength conversion of high-bit-rate signalsusing super structure grating distributed Bragg reflector lasers

Tunable wavelength conversion of a 10 Gb/s signal over a broad wavelength range of about 90 nm is achieved by using a super structure grating distributed Bragg reflector laser. The extinction ratio dependence of converted signal light on input signal light power and bias current to the laser active region is discussed. The extinction ratio becomes large when the input signal light power increases and the bias current decreases. Bit error rate measurements show that error-free, penalty-free wavelength conversion is achieved when the extinction ratio is large (12.5 dB) and that the bit rate which error-free wavelength conversion is possible increases as the input signal light power increases. Twenty Gb/s signal wavelength conversion is also demonstrated     

Performance Enhancement of Multiwavelength Conversion of RZ-DPSK Based on Four-Wave Mixing in Semiconductor Optical Amplifier

In this letter, we propose two methods to enhance the performance of multichannel wavelength conversion of return-to-zero differential phase-shift-keying signal in a semiconductor optical amplifier (SOA) based on four-wave-mixing effect. The first one is optimizing the relative time delay of the multichannel signal to reduce the crosstalk-induced penalty in SOA. The second one is using the synchronous clock pumping to raise the power of converted signal. The experiment on wavelength conversion of two channels at 10-Gb/s signal showed the power penalty was improved more than 1 dB in the first method and about 1.5 dB in the second method.     

Theoretical Study on Wavelength Conversion Based on Cross Phase Modulation Using Semiconductor Optical Amplifiers

Performances of wavelength converted signal by cross phase modulation (XPM) using semiconductor optical amplifiers (SOA's) were studied by the use of the multi-section model. Results show that they are related to both the phase arm bias current of the XPM wavelength converter and its operation. When the conversion is under the in-phase operation, the peak extinction ratio (ER) and the chirp frequency of the converted signal increase according to the decrease of the phase arm bias current, but the input signal power dynamic range decreases. When the converter is under the out-of-phase operation, the chirp frequency decreases with the decrease of the phase arm bias current, while the peak ER and the input power dynamic range keep almost the same when the phase arm bias current changes.     

High-Quality Grouped-Wavelength Conversion and Dynamic Switching Using Multiple-QPM LiNbO $_{3}$ and TLA

We demonstrate dynamic grouped-wavelength conversion using multiple quasi-phase-matched LiNbO$_{3}$ modules and a tunable laser diode array. A high signal-to-noise ratio of larger than 45 dB is obtained for the converted signals. The power penalty of the wavelength converter is confirmed to be less than 0.2 dB.      

Tuning technique to optimize input power of a cross-phase modulation wavelength converter

This paper proposes a tuning technique to optimize the input power of a cross-phase modulation wavelength converter (XPM-WC). The focus is on an output signal whose wavelength is the same as the input signal. The optimum input power can be easily set by keeping the output signal (not converted signal) power constant. Input continuous-wave (CW) power should be increased or decreased with increasing or decreasing input signal power so that the output signal power stays fixed at the optimum level. Observing the eye pattern of the converted signal is unnecessary. Wavelength conversion from a fixed optical channel to a random one (30 channels with 100-GHz spacing) is successfully demonstrated by using this technique. A low-power penalty (<1dB) and a low-power fluctuation (<1dB) were confirmed in all optical channels. An XPM-WC unit containing a variable CW light source and its level controller were fabricated and simultaneous and automatic operation was confirmed.     

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。