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。     

C-band EDFA级联及增益锁定

从输出光功率、信号增益、噪声指数等几个方面分析了 C- band全带 EDFA的特性 ,并针对 DWDM系统对 EDFA的各项指标如噪声指数、输出功率、增益锁定、增益平坦等的要求 ,着重分析 EDFA级联后对系统的影响 .实验结果为 :对 32波 DWDM系统 ,EDFA6级级联模拟 5× 2 5d B传输实验 ,增益平坦度为 3.5d B,光信噪比 >2 7d B,信道增减造成增益变化 <0 .6d B.     

EDFA gain transients: experimental demonstration of a low cost electronic control

Er-doped fibre amplifier (EDFA) gain transients are dynamic performance-degrading effects that need to be effectively suppressed in next-generation reconfigurable optical networks. In this paper, we experimentally assess the feasibility of an electronic dynamic gain control based on low-cost optoelectronic components, showing that a linearized electrical circuit and a control bandwidth smaller than 1 MHz can achieve the same performance as the commonly proposed all-optical feedback solutions.     

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.     

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。     

L波段增益可调放大器研究

文章首先分析了长波段(L波段)放大器的关键问题,然后对L波段放大器的特性和几种光路结构进行了模拟分析,并在此基础上提出了一种L波段增益可调的三级级联的放大器光路结构,给出了测试结果.测试结果表明,采用合理的光路结构可以实现具有高增益、增益平坦和较低噪声指数的L波段增益可调放大器.     

Tunable coherent optical transversal EDFA gain equalization

In this paper, we propose a fiber amplifier gain equalizer using a coherent optical transversal filter. The gain equalizer is tunable and has a bandwidth in the order of 30 nm. We also study the effects of different parameters such as input signal power pattern and the input pump power on the gain profile of the amplifier. The results show that, when the input signal power pattern changes, the amplifier does not maintain its gain profile. The gain profile has to be maintained in order to make the gain equalization effective. We show that, the pump input power can be adjusted so that the changes in the gain profile are compensated for. The gain profile varies quite slowly, hence compensation is feasible. As an example, we discuss the design of a gain equalizer for a system consisting of seven wavelength channels     

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.     

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.     

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.     

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.     

MSA增益可调EDFA在WDM系统中的应用

文章介绍了中间级接入(MSA)的概念和带有MSA功能的增益可调掺铒光纤放大器(EDFA)的原理及性能,详细分析了增益可调EDFA在密集波分复用(DWDM)系统中的应用场合以及多种性能表现,与传统固定增益EDFA相比,增益可调EDFA所具有的优点,并预测了带MSA功能的增益可调EDFA的应用前景.     

光网络中掺铒光纤放大器增益平坦性研究

论述了EDFA增益平坦化的主要方法,全面介绍了国内外光纤放大器增益平坦化的研究进展和成果,并对其优劣势进行了分析比较,提出了EDFA增益平坦技术的发展趋势.另外,还介绍了一种利用全局搜索算法来优化设计自身增益平坦EDFA这一较为新颖的方法.     

级联EDFA系统中偏振相关增益特性的研究

掺铒光纤放大器的偏振相关增益是导致放大器增益不平坦的一个重要原因,进而影响长距离光纤通信系统、长距离光纤传感系统的信号质量.本文从理论模拟角度研究了级联掺铒光纤放大器的偏振相关增益对光纤中所传输通信光信号的影响.重点研究了掺铒光纤非均匀展宽情况下,偏振相关增益受传输信号功率、信道个数、级联EDFA个数、等因素的影响,并给出了定性结论.     

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.     

Independent phase and magnitude control of an optically carriedmicrowave signal with a three-terminal vertical-cavity surface-emittinglaser

We demonstrate a compact integrated method for phase and magnitude control of an optically carried microwave signal with no external high-frequency circuitry. Our device consists of a novel three contact VCSEL, which permits external control of both the cavity loss and gain. Independent control of the phase and magnitude of the optically carried signal is demonstrated. With reference to the small-signal rate equations, we show that such independent control is only possible given the extra degree of freedom offered by the three contact design     

Independent control of transconductance gain and input linear rangein a MOS linear transconductance amplifier

A linear self-biasing MOS transconductance amplifier is presented. A linear V-I transfer characteristic is obtained by square-rooting the drain current of a MOS transistor in the saturation region. The main advantage of the circuit is that its transconductance gain and input linear range can be adjusted independently. Simulation results are included to confirm the feasibility of the technique     

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℃。