Study of power transients in EDFA with gain stabilisation by alaser effect

Power transients at the output of amplifiers with gain stabilisation by a laser effect when switching on/off input channels, are theoretically studied using a simulation model and compared with experimental results     

EDFA增益控制技术

介绍了DWDM系统中EDFA增益控制技术的发展情况,包括增益平坦和增益锁定两方面内容,并对典型的实施方案进行了比较和分析,最后提出了增益控制技术的发展趋势。     

EDFA增益瞬态控制研究的最新进展

针对当前光分组与线路节点光放大高稳定性需求,依据电、光两种主流控制方案,阐明了掺Er3+光纤放大器(EDFA)带微调和无微调情况下,基于电的自动增益控制机理。综述了EDFA增益瞬态控制研究的最新进展。分析了各种增益控制方案的具体控制过程。呈现了这些控制方法所取得的阶段性成果。     

Independent control of EDFA gain shape and magnitude usingexcited-state trapping

Controlled use of excited-states of erbium are used to decouple the magnitude and shape of the gain spectrum of an erbium-doped fiber amplifier (EDFA) containing a low phonon energy glass. This makes it possible to operate a single EDFA at multiple gains without the gain flatness degradation referred to as dynamic gain-tilt. Dynamic gain-tilt free operation is demonstrated in the long-wavelength portion of the erbium gain spectrum using an erbium-doped ZBLAN fiber     

Equalization of nonuniform EDFA gain using a fiber-loop mirror

We have experimentally demonstrated cascaded EDFA gain equalization using a fiber-loop mirror (FLM) acting as a linear wavelength filter. By changing the intra-loop polarization, the FLM passband center wavelength can be tuned. Additionally, there is some ability to change the bandwidth and filter slope of the FLM. The FLM is used to equalize the nonuniform gain of a cascade of EDFAs. After 1500 km, the power differential is reduced from 30 to 2 dB for three WDM channels covering a 9-nm wavelength range.     

Effective suppression of signal-wavelength dependent transients in a pump-controlled L-band EDFA

Typical pump-controlled L-band erbium-doped fiber amplifiers (EDFAs) in a feed-forward scheme give significant transients due to gain difference on wavelength of input signal when only a few channels are left. The fiber Bragg grating added pump-controlled L-band EDFA eliminates the wavelength dependent gain difference and transients.     

掺铒光纤放大器增益和噪声研究

文章首先介绍了掺铒光纤放大器(EDFA)的结构和工作原理,然后运用能级理论和激光原理,深入全面地分析了影响EDFA增益和噪声的主要因素,得出了EDFA增益和噪声与泵浦功率、泵浦方式、输入信号光功率和掺铒光纤长度等关系的一些重要结论,并且通过实验进一步验证了这些结论;提出了提高EDFA增益,减小噪声系数的方法;最后根据文中得出的结论,设计了一种高增益低噪声的C波段EDFA光路,该光路已经应用于工程实践中.     

WDM EDFA gain characterization with a reduced set of saturating channels

The advent of EDFA-based dense WDM places demanding optical source requirements for EDFA characterization. An iterative method is proposed here, based on a homogeneous amplifier model, to calculate the required signal conditions for WDM testing with a reduced set of saturating channels and a broad-band noise probe. EDFA gain measurements demonstrating this reduced-source technique agree to within 0.2 dB to those obtained with a four-channel WDM system operating near 1.55 /spl mu/m.     

一种EDFA温控电路的分析

根据掺铒光纤放大器(EDFA)模块对泵源温度的严格要求,设计了一种双回路温控系统。该系统可使载体温度迅速达到给定的温度;通过微机的精确测温和对给定值的微调修正,使温控精度达到了±0.03～±0.05℃。     

对EDFA增益和自发辐射噪声的研究

阐述了掺铒光纤放大器的放大原理，给出了计算放大器增益和自发辐射噪声的公式，并且给出了增益和噪声与掺铒光纤长度、泵浦功率、输入信号功率之间的关系。     

利用Optisystem仿真研究EDFA增益的影响因素

利用Optisystem软件建立EDFA系统,对EDFA增益的影响因素进行了分析.通过系统仿真分析,根据影响EDFA增益的因素,确定影响EDFA增益的最佳因素参数,验证了EDFA仿真系统的正确性和设计方案的可行性,更加准确地得到最佳优化设计方案.     

An EDFA gain control and power monitoring scheme for fault detection in WDM networks by employing a power-stabilized control channel

Schemes are proposed for the highly reliable gain control of erbium-doped fiber amplifiers (EDFAs) and for power monitoring to detect faults in wavelength-division-multiplexing (WDM) networks. These schemes employ one WDM channel (a control channel). The EDFA gain and output power levels are controlled by monitoring the control channel power that is automatically controlled and stabilized in the node. This prevents the uncontrolled EDFA operation that might result from any serious change in the control channel power. The use of a power stabilized control channel for power monitoring makes it possible to detect transmission system faults correctly because the monitoring of the control channel power is unaffected by the amplified spontaneous emission (ASE) generated in the EDFA. We also report experimental results on the dependence of the transient response of the EDFA gain and output power on the signal channel power and channel number input into the EDFA, when the power of the control channel changes due to problems with its light source. Numerical calculation of the gain transience explains the experimental results.     

一种用于接收机的低功耗自动增益控制环路

This paper proposes a new structure to lower the power consumption of a variable gain amplifier (VGA) and keep the linearity of the VGA unchanged. The structure is used in a high rate amplitude-shift keying (ASK) based IF-stage. It includes an automatic gain control (AGC) loop and ASK demodulator. The AGC mainly consists of six-stage VGAs. The IF-stage is realized in 0.18 μ m CMOS technology. The measurement results show that the power consumption of the whole system is very low. The system consumes 730 μ A while operating at 1.8 V. The minimum ASK signal the system could detect is 0.7 mV (peak to peak amplitude).     

A low power automatic gain control loop for a receiver

This paper proposes a new structure to lower the power consumption of a variable gain amplifier(VGA) and keep the linearity of the VGA unchanged.The structure is used in a high rate amplitude-shift keying(ASK) based IF-stage.It includes an automatic gain control(AGC) loop and ASK demodulator.The AGC mainly consists of sixstage VGAs.The IF-stage is realized in 0.18μm CMOS technology.The measurement results show that the power consumption of the whole system is very low.The system consumes 730μA while oper...     

用光纤环路镜实现WDM系统中的EDFA增益均衡

EDFA对不同波长的光产生的增益不同 ,这种增益不平坦特性成为 WDM系统中高速率、大容量信息传输的障碍 ,因此对 EDFA的增益进行均衡就显得特别重要。介绍用光纤环路镜实现 EDFA增益均衡的机理 ,并进行了实验 ,结果表明该方法简单易行 ,均衡效果显著     

A high-performance monolithic IF amplifier incorporating electronic gain control

A direct-coupled monolithic IF amplifier that incorporates an active gain control stage and exhibits a power gain of 50 dB and an AGC range of 60 dB at 50 MHz is described. This circuit has negligible change in either input or output admittance, and has excellent signal linearity over the full range of gain control. Experimental and theoretical analyses are made of the large signal response, stability, available gain, and noise behavior of the circuit. An application to color television is discussed in which the functions of the 45-MHz IF amplifier and the dc-AGC circuitry are fabricated on a single die.     

低成本电容式触摸控制设计

电容式触摸按键技术由于电路相对简单，只需一个微处理器和一些外围电路就可实现对按键的触摸检测和控制，因而适用于许多家用电器。通过对现有电容式触摸控制电路的分析，本着降低成本和提高可靠性的原则，进行软硬件协同设计，完成低成本电容式触摸控制设计。     

A model for the prediction of EDFA gain in a space radiation environment

Erbium-doped fiber amplifiers (EDFAs) were irradiated with /sup 60/Co /spl gamma/-rays up to a total dose of 3 kGy. Gain measurements and 1310-nm absorption were achieved during the irradiation to characterize the radiation-induced damage on the fiber. A model based on classical equations was developed to perform accurate predictions of the effects of radiation on EDFAs. This model was shown to be consistent with the experiment at various dose rates and temperatures, therefore allowing the extrapolation to a space environment simulation.     

电子对抗环境下AGC设计与实现

自动增益控制电路(AGC)是数字接收机的重要组成部分,用以减小量化损耗.通过分析数控可变增益放大器(VGA)的工作原理,提出AGC工程实现算法.同时分析了算法的稳态误差,给出了误差改善措施.基于AD8348芯片的工程实测结果表明,该算法能够较好地实现增益控制,满足电子对抗环境下的应用需求.     

Extrapolation of radiation-induced EDFA gain degradation at space dose rate

A model to predict the gain of an EDFA in an ionising environment is used to perform extrapolations at other doses and dose rates than those used for testing. Not only is good agreement found for doses up to five times higher than the test dose, but also lower dose rate extrapolation results reassure as far as introducing this device within satellites is concerned.