ASE spectral slice gain-clamping of EDFA

An erbium-doped (Er-doped) fiber amplifier operating in the C-band is gain clamped, at about 26 dB with noise figures below 6 dB by multiple fiber Bragg gratings. These gratings are placed at the amplifier output with center wavelengths in between communication channels so that unwanted amplified spontaneous emission is removed but put to good use. A 0.5-dB gain compression point at -15 dBm of input signal powers for two simultaneous signal channels is also demonstrated.     

Optimum pumping configuration for L-band EDFA incorporating ASE pump source

L-band gain improvement through usage of secondary pumping sources in the form of amplified spontaneous emission (ASE) was conducted. A simulation of the three-level rate equation that precedes the experimental approach provides a limited overview of the behavior of various inputs into the active medium-the erbium-doped fiber. Gain improvement as high as 6 dB was attained while incurring minimal noise figure penalty; in this case as low as 1 dB. For an L-band amplifier system employing ASE to improve gain, pumping the system counterdirectionally with ASE while the 980- or 1480-nm pumps are being used in a copropagating configuration would yield the best overall performance in terms of gain.     

EDFA-ASE光源在测试技术中的应用

报导了掺铒光纤放大器（ＥＤＦＡ）在测试技术中的应用情况。按照文中介绍的方案，把ＥＤＦＡ配置成光源来用，它在１５３０～１５７０ｎｍ 间输出光功率大于１０ｍＷ；稳定度为±０．０２ｄＢ。用这一光源测试了几种光纤器件的主要性能指标，与用调谐激光源测试相比较，两种光源测试的结果是一致的，这表明这种ＥＤＦＡ－ＡＳＥ非相干波长可调光源在测试技术中使用是完全可行的。     

WDM系统中级联EDFA的自动增益控制

综合分析了WDM系统中掺铒光纤放大器(EDFA)的主要性能指标，以及内外部工作条件的关系，讨论了有关EDFA的动态增益锁定与平坦机制。提出了更加优化的WDM系统中EDFA的自动增益控制的解决方案，并设计相关了试验，给出了采用本方案实现EDFA动态增益控制的分析结果。最后，指出了各种科技产品的问世，为EDFA的自动增益控制研究提供了更加广阔的思路和便利的条件。     

S-band single-stage EDFA with 25-dB gain using distributed ASE suppression

We propose a novel compact design for a single-stage S-band erbium-doped fiber amplifier, wherein distributed suppression of C-band amplified spontaneous emission is provided by optimized bend loss in a coaxial core fiber. Simulations show that /spl sim/25-dB unsaturated gain over 30-nm bandwidth (1495-1525) nm is achievable with the designed module, using a nominal pump power of 500 mW. The noise figure of the amplifier varies between 4.5 and 8 dB from 1495 to 1525 nm. By proper designing, we have also ensured that the gain ripple over the entire 30-nm bandwidth is 相似文献   

正反向泵浦下掺铒光纤放大器的增益与自发辐射特性的研究

本文论述了掺铒光纤放大器在正向泵浦、反向泵浦时，它的增益与自发辐射特性的不同，通过对电子工业部第四十六研究所研制的掺铒光纤吸收谱的测量，计算了正向泵浦、反向泵浦时，泵浦光、某一波长的荧光功率、荧光总功率及信号光功率随光纤长度的变化，分析了正反向泵浦时，掺铒光纤放大器的荧光谱与增益谱，并讨论了双向泵浦情况下，放大器增益与光纤长度的关系。     

Coupled structure for wide-band EDFA with gain and noise figureimprovements from C to L-band ASE injection

We propose a novel structure for C plus L-band silica based wide-band erbium-doped fiber amplifiers (W-EDFA's), which use backward amplified spontaneous emission from the C-band EDFA as the pump-mediating injection source for the L-band amplifier unit. Experimental results show gain and noise figure improvements of over 2.6 dB and 0.6 dB, respectively, at -3.5 dBm of L-band input signal power. Spatially resolved numerical analysis confirms the pump-mediating effect of C-band backward ASE in the L-band EDFA for the gain and noise figure improvement, which also provides better understanding on the dynamics of C-band injection seed methods     

Reference level free multichannel gain equalization and transientgain suppression of EDFA with differential ASE power monitoring

We demonstrate a novel means of gain flatness monitoring and control of a multichannel gain flattened erbium-doped fiber amplifier (EDEA), which does not require a gain dependent reference level for the feedback loop. Using the difference of amplified spontaneous emission/probe powers extracted from the edges of the gain-flattened bandwidth, gain flatness monitoring, equalization, and transient gain suppression can be achieved regardless of the steady-state gain value of an EDFA. This approach eliminates the need of elaborate measurements for the determination of control parameters for each application, making it possible to use the same circuitry for different amplifiers. Measurements show flatness control within 0.03 dB/10 nm, at the same time the suppression of time-dependent gain excursion to below 0.2 dB     

EDFA增益控制与差错检测的功率监测方案

介绍了波分复用网络中EDFA高可靠增益控制与电压监测的差错检测方案.EDFA增益与输出电压通过监测控制信道电压来实现控制.功率检测中采用功率稳定的控制信道可以正确检测传输系统中的错误.     

EDFA瞬态增益特性控制方法

掺铒光纤放大器(EDFA)的瞬态增益特性已成为影响密集波分复用(DWDM)网络性能的一个重要因素.文章描述了EDFA自动增益控制的基本原理,总结了当前几种抑制瞬态增益波动的自动增益控制技术及典型实施方案,并比较了其优缺点.最后给出了对未来自动增益控制技术发展的看法.     

DRM发射机自动延时调整分析

相关分析是当前应用较广且有效的一种延时估计方法。本文朝述了用相关分析原理估算DRM发射机包络和相位两路司延时差的方法,并用仿真验证了采用最大似然估计宙相关算法的计算精度,为DRM发射机实现自动延时调整提供了一个可行的理论解决依据。     

DRM发射机自动延时调整的分析与设计

在模拟调幅发射机数字化改造过程中,一个关键性问题是包络和相位两路信号间的延时控制,该延时的存在会影响发射信号的性能.本文针对该问题,提出了一种DRM发射机自动延时调整的技术解决方案,详细说明了其中两大关键内容--延时值的获取和调整延时的实现.     

掩模硅片自动对准误差校正算法

为了改善对准精度,对100nm级线宽尺寸建立了掩模硅片自动对准数学模型,应用于同轴离轴混合对准系统的硅片模型、掩模模型以及工件台模型中。掩模硅片自动对准算法决定机器坐标系、掩模坐标系、硅片坐标系相互的位置关系,可很好地校正由掩模硅片引起的平移、线变、旋转、正交性的偏差。     

混合RFA/EDFA与EDFA的QoS性能比较

介绍了采用EDFA系统与采用混合RFA/EDFA系统的两种WDM网络,在放大器正常放大、遭受大功率信号攻击、遭受大功率噪声攻击三种环境下进行研究,通过理论分析和仿真试验得出,在系统QoS性能方面,采用混合RFA/EDFA的系统优于只采用EDFA的系统。     

掺铒光纤放大器噪声特性的全面分析

本文对掺铒光纤放大器（ＥＤＦＡ）的噪声特性进行了全面的分析。把光信号和ＥＤＦＡ中放大自发辐射（ＡＳＥ）产生的量子噪声，以及信号－ＡＳＥ拍频噪声和ＡＳＥ－ＡＳＥ拍频噪声一并加以考虑。通过数值模拟，给出了不同信号功率和泵浦功率下的ＥＤＦＡ噪声系数。这些结果对优化ＥＤＦＡ的工作参量及其工程制作具有一定的指导作用。     

功率因数校正技术及不同控制策略研究

功率因数校正电路广泛应用于交-直电源变换电路中,以消除电力系统的谐波,提高功率因数。为此,对典型的有源PFC的Boost电路进行原理性分析,并对有源功率因数校正的各种控制方法从不同角度进行分析和比较,如连续导通模式、不连续导通模式和临界导通模式,平均电流模式、电流峰值模式和电流滞环控制等。最后以L6561为例说明各种功率因数控制方法不是独立而是相互联系的,实际应用中应该结合考虑各方面具体情况来进行选择。     

Error-Correcting Codes for Automatic Control

Systems with automatic feedback control may consist of several remote devices, connected only by unreliable communication channels. It is necessary in these conditions to have a method for accurate, real-time state estimation in the presence of channel noise. This problem is addressed, for the case of polynomial-growth-rate state spaces, through a new type of error-correcting code that is online and computationally efficient. This solution establishes a constructive analog, for some applications in estimation and control, of the Shannon coding theorem.      

水质自动监测控制系统

水质自动监测控制系统是一套含水质自动分析仪、数据采集、站点控制、远程监控、数据发布于一体的在线全自动监控系统。该系统实现了对水质的实时连续监测和远程控制,能及时发现主要流域水质的异常变化,追踪污染源,对水质污染迅速做出预警预报,从而有效避免水质污染事故的扩大。