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.     

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.     

EDFA的增益控制及平坦技术研究

对EDFA的增益箝制和平坦的基本原理进行了介绍,对实现EDFA增益箝制和平坦的不同技术途径的机理和结构举例进行了扼要分析,给出了采用光纤光栅反射镜来实现EDFA全光增益箝制的仿真分析结果,指出了EDFA的增益控制及其平坦的技术发展方向。     

EDFA增益箝制技术研究

介绍了EDFA增益箝制基本原理 ,对实现EDFA增益箝制的不同技术途径的箝制机理和结构进行了举例及扼要分析 ,给出了采用光纤光栅反射镜来实现EDFA全光增益箝制的仿真分析结果     

掺铒光纤放大器及其在波分复用系统中的应用

介绍了掺铒光纤放大器（EDFA）的原理、组成结构和所用元器件，阐述了EDFA的增益、噪声和增益谱特性，并对EDFA应用于波分复用（WDM）系统中带来的增益谱平坦问题进行了讨论。     

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.     

EDFA的增益控制及平坦技术研究

对EDFA的增益箝制和平坦的基本原理进行了介绍，对实现EDFA增益箝制和平坦的不同技术途径的机理和结构举例进行了扼要分析，给出了采用光纤光栅反射镜来实现EDFA全光增益箝制的仿真分析结果，指出了EDFA的增益控制及其平坦的技术发展方向。     

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     

增益可控的小型化掺铒光纤放大器的研制

介绍了一种利用980nm泵浦源、两段式光路结构设计和实现的增益可控的小型化掺铒光纤放大器(EDFA)的方法.首先应用谱求解的方法对EDFA的理论模型进行了研究,基于该模型对两段式EDFA进行优化,优化设计后的EDFA的增益比单段式结构提高了1.9dB,反向自发辐射噪声也得到了抑制.给出了小型化EDFA系统设计框图和主要温控电路结构,对EDFA系统的泵浦源工作状态、增益及光信噪比等参数进行了测量,得到了与理论建模相符合的结果.     

增益平坦滤波器的几种实现技术

EDFA的增益平坦化是DWDM系统中的关键问题,介绍了EDFA增益平坦滤波器的实现技术原理并对其关键技术参数进行了比较,认为啁啾光栅增益平坦滤波器是--较好的选择.试验表明,在高功率EDFA中加入啁啾光栅增益平坦滤波器,其增益平坦度可控制在±0.3dB以内.     

Performances of Erbium‐Doped Fiber Amplifier Using 1530nm‐Band Pump for Long Wavelength Multichannel Amplification

The performance of a long wavelength‐band erbium‐doped fiber amplifier (L‐band EDFA) using 1530nm‐band pumping has been studied. A 1530nm‐band pump source is built using a tunable light source and two C‐band EDFAs in cascaded configuration, which is able to deliver a maximum output power of 23dBm. Gain coefficient and noise figure (NF) of the L‐band EDFA are measured for pump wavelengths between 1530nm and 1560nm. The gain coefficient with a 1545nm pump is more than twice as large as with a 1480nm pump. It indicates that the L‐band EDFA consumes low power. The noise figure of 1530nm pump is 6.36dB at worst, which is 0.75dB higher than that of 1480nm pumped EDFA. The optimum pump wavelength range to obtain high gain and low NF in the 1530nm band appears to be between 1530nm and 1540nm. Gain spectra as a function of a pump wavelength have bandwidth of more than 10nm so that a broadband pump source can be used as 1530nm‐band pump. The L‐band EDFA is also tested for WDM signals. Flat Gain bandwidth is 32nm from 1571.5 to 1603.5nm within 1dB excursion at input signal of –10dBm/ch. These results demonstrate that 1530nm‐band pump can be used as a new efficient pump source for L‐band EDFAs.     

Pump wavelength-dependent spectral-hole burning in EDFAs

Gain-difference spectra are used to show that 980-nm band pump wavelength changes can significantly effect spectral-hole burning (SHB) in erbium-doped fiber amplifiers (EDFAs). Gain measurements made using a number of different signal and pump wavelengths help to characterize the underlying inhomogeneous spectral properties of EDFAs and a framework for modeling these effects is presented. Despite the difficulty of obtaining the needed subpopulation specific cross section spectra, this model can be used to explain seemingly anomalous changes in the gain spectra of EDFA as a result of changes in signal or pump wavelength     

Gain control in erbium-doped fibre amplifiers by an all-optical feedback loop

An all-optical feedback loop is demonstrated which effectively suppresses slow, signal-induced gain fluctuations in Er-doped fibre amplifiers (EDFAs). Gain control is achieved by operating the amplifier in a ring-laser configuration. The working principle is shown theoretically and experimentally by coupling a selected wavelength of the ASE at the output of the EDFA back to the input. Such a feedback loop, which can be fabricated out of all-fibre passive components, could be easily implemented in any system using EDFAs.<>     

Output power and SNR swings in cascades of EDFAs for circuit- andpacket-switched optical networks

A simple dynamic model of the erbium-doped fiber amplifier (EDFA) that includes self-saturation by amplified spontaneous emission (ASE) is used to analyze the power and signal-to-noise ratio (SNR) transients in wavelength division multiplexed (WDM) optical networks in which signals cross chains of EDFAs from source to destination. The model, which consists of solving sequentially one ordinary differential equation per amplifier, is used to (1) determine power and SNR excursions in the surviving channels along a chain of 35 EDFAs during isolated add-drop events in a 16-channel WDM circuit switching scenario and (2) run Monte Carlo simulations of the first five EDFAs of the same chain fed by burst-mode packet switching traffic on each of the 16 channels. Each packet source is modeled as an ON-OFF asynchronous transfer mode (ATM) source, with ON and OFF times having a heavy-tailed Pareto distribution. The aggregate source model is asymptotically self-similar, and well describes multimedia packet communications. The results are used to examine the influence of average network utilization and source ON-OFF time variance on the probability density function of signal power and SNR at each EDFA output. We demonstrate that self-similar traffic generates sizable power and SNR swings, especially at low network utilization. The simulations also indicate sizable broadening of the power and SNR density functions along the cascade of EDFAs, reaching levels in excess of 9 dBm and 4 dB for the power and SNR swings, respectively, at the 5th EDFA. The effect becomes more pronounced for longer EDFA chains. Such a large broadening may imply serious system impairments in burst-mode WDM packet networks     

Evaluation of the 800 nm pump band for erbium-doped fiberamplifiers

Performs a comprehensive experimental and theoretical investigation of methods for overcoming the excited-state absorption (ESA), which is the main obstacle to efficient pumping of erbium-doped fiber amplifiers (EDFAs) at 800 nm. The effects of ESA on gain can be reduced at the cost of an additional noise penalty by adopting bidirectional pumping or by pumping in the long-wavelength tail of the ground-state absorption (GSA) band. The GSA and ESA cross-section spectra on the glass host material. One of the most promising hosts, fluorophosphate, is compared to Al/P silica in a detailed analysis based on a quantitative numerical model. It is predicted that 2-3 dB less pump power is required for the fluorophosphate EDFA. For Al/P-silica EDFAs, it is found that ~7-dB-higher power is required when pumping in the 800 nm band than for pumping at 980 and 1480 nm     

光纤CATV用掺铒光纤大器的简化分析

在不考虑放大自发辐射（ASE）对掺饵光纤放大器（EDFA）饱和特性影响的条件下,推出了掺饵光纤放大器（EDFA）三能级系统功率传输的解析表达式,简化了理论分析,所得结果也适用于二能级系统。根据该简化分析方法具有计算了前向泵浦时光纤CATV用掺饵光纤放大器（EDFA）的信号增益曲线。计算表明,当信号增益约在25dB以下,即在光纤CATV用掺饵光纤放大器（EDFA）的工作范围内,简化分析所得的计算结果与较精确的数值计算结果一致。     

沿传输方向浓度渐变掺铒光纤放大器的模型

提出了两种掺铒浓度渐变的分布式光纤放大器（ｄ－ＥＤＦＡ）模型：沿传输方向，掺杂浓度单调线性下降与掺杂浓度线性由大到小，由小到大两次变化的ｄ－ＥＤＦＡ，用传输方程研究了不同渐变系数下，ｄ－ＥＤＦＡ的各种特性。     

SUPER PON-a fiber to the home cable network for CATV andPOTS/ISDN/VOD as economical as a coaxial cable network

A complete super PON fiber to the home cable network as economical as the classic coaxial cable network, designed for application in the local loop is presented. The concept uses high power lasers, remote pumped erbium doped fiber amplifiers (EDFAs) to reduce cost by high splitting ratio, economical receivers for the downstream direction and economical CD player lasers for the upstream direction. Several novel technical solutions for this application (a new method to avoid stimulated Brillouin scattering (SBS), remote pumping of the EDFA and a compensating technique to adapt the CD laser to the normal fiber) are presented     

长波段掺铒光纤放大器的设计新方案

本文较为全面的阐述了近几年来国内外对长波段掺铒光纤放大器(L—band EDFA)的研究情况，从设计EDFA最主要的技术关键—铒光纤与泵浦源两方面分析了其工作原理，总结出新的设计思路与方案，并提出了一些新的研究点。同时，也分析、介绍了一些结构新颖的宽带(C L band)EDFA。     

铋镓铝共掺的高浓度掺铒光纤及放大器

研制出了铋镓铝共掺的高浓度掺铒光纤,这种掺铒光纤在1 530 nm处的吸收系数达到了28.5 dB/m.利用这种铋镓铝共掺的高浓度掺铒光纤制成了C波段和L波段的掺铒光纤放大器(EDFA),测试这两种放大器的荧光谱和增益谱线.利用2.5 m的高浓度掺铒光纤制作的C波段EDFA就实现了高增益.利用10 m这种掺铒光纤制作的L波段放大器实现了有效的I波段放大.