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。     

Cross-phase modulation in an L-band EDFA

We measure the cross talk in a wavelength-division-multiplexed (WDM) system arising from cross-phase modulation (XPM) in an L-band erbium-doped fiber amplifier (EDFA). This effect has the potential of becoming the dominant nonlinear crosstalk mechanism in L-band WDM systems using standard fiber. We discuss how appropriate amplifier design can reduce the XPM in the EDFA     

Gain enhancement in L-band EDFA through a double-pass technique

An improvement of gain in the long-wavelength band (L-band) is observed by double passing the forward amplified spontaneous emission and signal in the erbium-doped fiber (EDF) using a circulator, unlike conventional single pass amplification. A gain enhancement as high as 11 dB is obtained for a 1570-nm signal with an input power of -20 dBm at 98 mW of pump power. However, a noise figure penalty of about 2 dB is observed     

L波段EDFA的仿真和实验

文章介绍了L波段掺铒光纤放大器(EDFA)的理论模型，并根据L波段EDFA的实验结果对理论模型进行了验证，实验结果和理论分析相吻合．     

Gain clamping in two-stage L-band EDFA using a broadband FBG

A gain-clamped long wavelength band erbium-doped fiber amplifier (L-band EDFA) with an improved gain characteristic is demonstrated by simply adding a broadband conventional band (C-band) fiber Bragg grating (FBG) in a two-stage amplifier system. The FBG reflects backward C-band amplified spontaneous emission (ASE) from the second stage back into the system to clamp the gain. The gain is clamped at about 22.4 dB with a gain variation below 0.4 dB for input signal powers of -40 to -15 dBm. Compared with an unclamped amplifier of similar noise figure values, the small signal gain has improved by 2.4 dB due to the FBG which blocks the backward propagating ASE. At wavelengths from 1570 to 1600 nm, gain of the clamped amplifier varies from 19.4 to 26.7 dB. The corresponding noise figure varies by /spl plusmn/0.35 dB around 5 dB, which is not much different compared to that of the unclamped amplifier.     

L-带掺铒光纤放大器的研究与进展

通过理论计算，比较了C－带掺铒光纤放大器和L－带掺铒光纤放大器的增益特性，并较为全面地阐述了近几年来国内外对L－带掺铒光纤放大器的研究情况。通过对L－带掺铒光纤放大器工作原理的分析，总结出新的设计思路与方案，提出了一些新的研究点。     

L波段EDFA特性研究及优化设计

基于Giles模型对C-EDFA放大的自发辐射谱进行了研究,得出了铒纤增益随长度增加向长波段位移的结论.分析了L-EDFA和C-EDFA中各光束的传输特性,为L-EDFA低泵浦转换效率提供了合理的解释,并研究了L-EDFA本征平坦增益特性,确定了形成平坦增益的最佳粒子数反转条件(～40%).最后利用EDFA前端加入一个光纤环行镜反射后向ASE光这种新颖的结构,较好地解决了L-EDFA泵浦效率低的问题,相比于传统的链路结构泵浦转换效率提高了8.76%.     

L波段EDFA的优化设计和实验验证

基于Giles模型,对L波段掺Er光纤放大器(EDFA)的特性进行了数值模拟,分析了采用高掺杂Er纤放大器输出性能的改善。根据数值分析的结果进行了优化设计,使用9m长的高掺杂Er光纤进行了实验研究。实验结果表明．在泵浦功率为100mw时,小信号增益在10dB以上,噪声指数小于6dB。     

温度对L波段EDFA增益斜率影响的实验研究

实用的L波段EDFA(掺铒光纤放大器)常采用多段铒纤和多泵浦的复杂结构。对一种复杂结构的L波段EDFA的温度特性进行了实验研究,发现在不同的输入光功率下,L波段短波侧(约1 570～1 582nm)的增益谱可按相反的方式随温度而变化,并从理论上解释了此现象。实验结果表明,铒纤的温度和增益斜率之间仍然存在很好的线性关系。控制铒纤温度就可以调整L波段EDFA的增益斜率,获得平坦的增益。     

Gain enhancement in L-band loop EDFA through C-band signal injection

Gain enhancement provided in L-band erbium-doped fiber amplifier (EDFA) with loop configuration and through C-band signal injection is experimentally demonstrated and compared with conventional single-stage L-band EDFA design. Significant backward amplified spontaneous emission suppression in C-band and pump conversion efficiency increase in L-band were observed for varying C-band seed signal wavelength and power levels. Gain and noise figure (NF) performance of loop design L-EDFA is compared with the conventional bidirectionally pumped single-stage L-EDFA design. Gain and NF measurements in the loop configuration have resulted in an up to 9.5-dB increase in gain and up to 2.6-dB degradation in NF at a moderate signal wavelength of 1585 nm.     

A low-noise L-band EDFA with a 1500-nm Raman-pumped dispersion-compensating fiber section

This report presents a low-noise L-band erbium-doped fiber amplifier (EDFA) with a dispersion-compensating Raman amplifier. With an optimized prestage and 1500-nm Raman-pump laser diodes, the proposed EDFA achieved an internal noise figure of less than 4.5 dB over a 33-nm flat gain bandwidth within 0.5 dB at -2 dBm of large signal input power.     

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.     

L-band EDFA泵浦转换效率提高的实验研究

研究C—band种籽光对L—band EDFA泵浦转换效率的影响，实验表明，在L—band EDFA中注入C—band种籽光时，可以有效提高泵浦转换效率。     

级连L波段EDFA优化的数值模拟与实验

对级连结构的L波段EDFA进行了优化设计.首先用加拿大Optiwave的OptiAmplifier4.0数值模拟了在其他条件确定情况下两级光纤长度比例变化对放大器性能的影响,在优化光纤长度比例的基础上,为了得到更宽的L-EDFA的本征平坦增益谱,进一步优化了前后级泵浦功率.在上述条件下利用42 m的铒纤得到实验结果为:ASE谱3 dB带宽1566.84～1606.80 nm(40 nm).在L波段(1570～1605 nm),小信号平均增益约为25 dB,增益不平坦度为±1 dB,噪声指数约为5 dB.     

Improvement of gain and noise figure in double-pass L-band EDFA by incorporating a fiber Bragg grating

An obvious improvement on both the gain and noise figure (NF) is demonstrated in the new double-pass L-band erbium-doped fiber amplifier (EDFA) with incorporating a fiber Bragg grating (FBG). Compared with the conventional L-band EDFAs, the gain is improved by about 6 dB in the new configuration for a 1580-nm signal with an input power of -30 dBm at 60 mW of 980-nm pump power. It is important that the NF is greatly reduced in the new configuration, as the FBG greatly compresses the backward amplified spontaneous emission. For the economical utility of pump power and erbium-doped fiber length, such a configuration may be a very competitive candidate in the practical applications of L-band EDFAs.     

基于高双折射光纤环形镜L-band EDFA增益平坦实验

采用高双折射光纤环形镜进行了L bandEDFA的增益平坦实验。调节环内的偏振控制器,可以改变环的反射谱或透射谱的位置和深度;改变环内高双折射光纤的长度,可以改变环的反射谱或透射谱的波长响应周期。适当选取双折射光纤的长度和调节偏振控制器使环形镜的反射谱EDFA的增益谱相匹配。实现了L bandEDFA的增益平坦。双级结构的L bandEDFA经高双折射光纤环形镜平坦后,在1570～1595nm范围内,平均增益18.6dB,增益平坦度达±0.57dB。     

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     

C波段和980 nm抽运的两段级联L波段掺铒光纤放大器

提出了由C波段和传统的 980nmLD两段级联抽运L波段信号的结构 ,C波段的功率和波长由掺铒光纤激光器控制。从实验和理论上分析了注入不同波长和功率的C波段对其增益的影响。设计的掺铒光纤放大器(EDFA)结构 ,在C波段波长为 15 2 5nm ,注入功率为 5mW时 ,功率为 - 2 0dBm ,波长为 15 80nm的信号增益提高了 7 7dB。     

980nm和1480nm泵浦L波段EDFA的优化设计

文章研究了980nm和1480nm泵浦的L波段掺铒光纤放大器（EDFA）的设计与仿真，得出了同向泵浦和双向泵浦两种情况下的最佳泵浦波长配置。     

Wavelength and power dependence of injected C-band laser on pumpconversion efficiency of L-band EDFA

The effect of wavelength and power of an injected C-band laser on the pump conversion efficiency of a L-band erbium-doped fiber amplifier was studied via numerical simulation and experiment. In the studied C-band wavelength range of 1530-1560 nm, for higher injected power with longer wavelength, the backward output amplified spontaneous emission power is compressed more; but the residual laser power is greater due to the smaller emission coefficient at longer wavelength. Thus there is a best choice for injection wavelength and power. With an injection of -2 dBm at 1550 nm, 4.3 and 2.5 dB of gain enhancement for -12 and -2.6 dBm input at 1586 nm were achieved, respectively