光放大器现状及未来发展

综述光放大器的技术现状及未来发展 ,主要介绍掺铒光纤放大器 (EDFA)、掺铒波导放大器(EDWA)、半导体光放大器 (SOA)以及喇曼光纤放大器 (FRA)。最后比较了这几种放大器的发展趋势。     

混合式喇曼/掺铒光纤放大器特性及应用进展

介绍了光纤喇曼放大器的结构,分析了分布式喇曼放大器（DRA）的低噪声特性.对于Raman/EDFA（喇曼/掺铒光纤放大器）混合式光放大器的主要特性进行了深入讨论并介绍了它在波分复用光纤通信系统中的应用与进展.     

喇曼和掺铒光纤放大器在WDM系统中的应用

简述了掺铒光纤放大器和喇曼光纤放大器的工作原理,对比增益和噪声性能,讨论了其在波分复用系统中的应用。     

光纤放大器的研究动态

介绍了国内外光放大器的最新研究动态,主要包括掺铒光纤放大器、掺铥光纤放大器、光纤喇曼放大器及半导体光放大器,并指出相关放大器的发展趋势,最后对光纤放大器的特性进行了比较分析.     

基于EDFA+FRA的增益平坦补偿

采用光子转换理论和数值分析方法,研究了采用DCF光纤的喇曼放大器和掺铒光纤放大器组成的混合放大器在DWDM系统中的应用。通过对喇曼光纤放大器的光纤长度、泵浦功率的选择,使得混合放大器的总增益达到一定的平坦度;并分析设计了增益均衡器,让混合放大器最后的总增益达到更高的平坦度。     

光纤喇曼放大器的发展与应用

首先介绍了光纤喇曼放大器的发展情况和原理结构,与掺铒光纤放大器相比,指出光纤喇曼放大器的优点,然后在三种不同环境下,对混合FRA/EDFA放大与EDFA单独放大这前后两种放大技术的QoS性能进行了比较,最后介绍了FRA在SDH、CATV、WDM和企业存储网络中的应用.     

S-band光纤放大器的研究进展

主要介绍了几种S-band光纤放大器,包括光纤喇曼放大器(RFA)、增益位移掺铥光纤放大器(GS-TDFA)、掺铒光纤放大器(EDFA)和光学参量光纤放大器(OPA),综述了其原理、特点、研究现状及发展趋势。     

喇曼放大器再次使光纤传输容量提高

随着bit率增加到10Gb/s和更高,喇曼放大器开始挤进掺铒光纤放大器市场。大多数喇曼放大器的设计安排是分布式的,但是现在开始出现独立式的,或者集中式的喇曼放大器。     

高速光纤通信中的光纤放大器及其发展

光纤放大器是高速光纤通信中的重要器件之一,文章综述了掺铒光纤放大器、掺铥光纤放大器、喇曼放大器、布里渊放大器、参量放大器以及混合光纤放大器等的工作原理、结构和工作特性,并对今后的发展方向进行了讨论.     

掺铒光纤放大技术及其在密集波分复用系统中的应用

概述了掺铒光纤放大器的发展情况、原理及其在密集波分复用系统中的应用，重点阐述了掺铒光纤放大器与拉曼放大技术的组合应用，最后指出这两种技术的组合应用能明显提高长距离光纤通信系统性能，使掺铒光纤放大器具有更广阔的应用前景。     

Suppression of transient phenomena in hybrid Raman/EDF amplifier

Transient phenomena of hybrid Raman/erbium-doped fiber amplifier (EDFA) upon optical channel add-drop are investigated. The transient responses of surviving channels are resulted from the combined dynamics of Raman amplifier and EDFA. It is shown that the suggested method employing fast gain control of EDFA only can effectively suppress the transient variation of output power. The transient-suppressing hybrid Raman/EDFA is proven to be enough for wavelength-division-multiplexing networks including reconfigurable optical add-drop multiplexer and/or transparent optical cross-connect, if the optical switching speed is carefully chosen.     

Simultaneous Cancellation of Fiber Loss, Dispersion, and Kerr Effect in Ultralong-Haul Optical Fiber Transmission by Midway Optical Phase Conjugation Incorporated With Distributed Raman Amplification

An alternative application of distributed Raman amplification (DRA) for ultralong-haul optical fiber transmission is proposed. In our study, the DRA is employed in a transmission system using midway optical phase conjugation (OPC) for amplifying an optical signal and, at the same time, for constructing signal power evolution, which is symmetrical with respect to the midpoint of the system where the OPC is performed. Then, the nonlinear signal waveform distortions that are caused by the Kerr effect, as well as fiber dispersion, are almost completely compensated by the OPC, whereas the fiber loss is compensated by the DRA. Three possible symmetrical signal power maps - a power map that has a reverse sign of the power map that is caused by lump amplification, a flat signal power map, and an arbitrary symmetrical signal power map - are numerically designed by using appropriate Raman pump powers. We show that the flat power map exhibits smaller difference from the target and a higher optical signal-to-noise ratio and requires lower pump power than the other two power maps. Numerical simulation results demonstrate that, by employing the flat power maps with a span of 40 km, a single-wavelength signal whose data rate is 160 Gb/s can be successfully transmitted over 5000 km, and the Kerr effect is sufficiently suppressed near limitation due to the nonlinear accumulation of noise. Finally, we study the feasibility of expanding our method to wavelength-division-multiplexed signal transmission by designing a DRA gain with multiple-wavelength pumping to simultaneously obtain a flat power map and a wide-and-flat gain bandwidth. By using four-wavelength Raman pumps while carefully choosing pump wavelengths and their powers, we achieve the DRA gain that simultaneously gives a fluctuation of the signal power of only 3.5%, a gain ripple of only 5.3%, and, at the same time, a gain bandwidth of as wide as 46 nm.     

Application of Raman-distributed amplification to WDM transmissionsystems using 1.55-μm dispersion-shifted fiber

A numerical design method for wavelength division multiplexing (WDM) transmission systems employing distributed Raman amplification (DRA) is proposed. This method evaluates fiber nonlinear effects by considering the equivalent fiber loss with DRA. The method is used to evaluate the performance of WDM transmission systems in which DRA is employed in a 1.55-μm dispersion-shifted fiber (DSF) transmission line. Transmission limit and the optimum fiber input powers for 1550-nm band (C-band) and 1580-nm band (L-band) transmission are investigated. Results show that bidirectional pumping is the best approach to extending transmission distance. Furthermore, the transport limits of optical transport networks that use DRA and optical add/drop multiplexers are analyzed     

基于EDFA和级联RFA的混合光纤放大器的设计

基于EDFA的理论模型和受激拉曼散射效应的分析理论,利用EDFA和RFA的增益谱互补特性,对拉曼光纤放大器(RFA)采用两根光纤级联方式,研究并设计了EDFA与级联光纤的RFA相结合的混合放大器结构.仿真结果表明:在不使用增益均衡器的条件下,所设计的混合光纤放大器在输出端得到了近似相等的输出光功率,得到了增益平坦度为0.62 dB、波长带宽为70 nm(1 550～1 620 nm)的结果,在密集波分复用光通信系统中有重要的应用价值.     

拉曼放大器的基本原理及其在有线电视光纤网长距离传输中的应用

当前在残留边带调幅（AM-VSB）调制的外调制光纤有线电视系统中,为实现长距离传输普遍采用大功率掺铒光纤放大器（EDFA）,而大的入纤光功率在光纤的色散作用下存在严重的非线性失真,根据受激拉曼散射原理,提出分布式光纤拉曼放大器（DFRA）在长距离信号传输中的应用对改善组合二阶失真（CSO）起到明显的效果,并与EDFA对比实验验证了其结果。     

Segmented-clad fiber design for tunable leakage loss

This paper proposes a novel segmented-clad fiber (SCF) design in which the spectral variation of leakage loss of the fundamental mode can be finely tuned by varying the fiber parameters. A fiber with such optimized spectral variation of leakage loss should find application in the realization of inherently gain-flattened optical fiber amplifiers, wavelength filters, wavelength-flattened attenuators, etc. In this paper, the authors present SCF designs optimized for realizing inherently gain-flattened S-band erbium-doped fiber amplifier (EDFA) and high-gain discrete Raman fiber amplifier (RFA). Amplifier characteristics have been modeled in both cases, and simulations show that a 20-dB gain with /spl plusmn/0.9 dB of gain ripple over a 30-nm bandwidth in S-band is achievable with the designed EDFA based on the optimized SCF. In case of discrete RFA based on SCF, a 20-dB net gain with /spl plusmn/0.5-dB ripple is shown to be achievable over a 28-nm wavelength range in S-band.     

Performance of WDM fiber-radio network using distributed Raman amplifier

We investigate the impairment induced by stimulated Brillouin scattering (SBS) effect and noise characteristics of wavelength-division-multiplexing fiber-radio network assisted by distributed Raman amplifier (DRA) or erbium-doped fiber amplifier. Experimental results indicate that forward-pumping DRA can increase the link optical output power limited by SBS effect in downstream transmission and backward-pumping DRA can improve signal-to-noise ratio in upstream transmission, which is verified by binary phase-shift keying transmission experiments. Moreover, our experimental results show that DRA does not introduce additional impairment from interchannel crosstalk due to cross-phase modulation and degradation in spur-free dynamic range.     

高入纤功率光纤通信系统的可靠性研究

掺铒光纤放大器(EDFA)和拉曼放大器(FRA)的使用,使得光纤通信系统中的入纤功率有了很大的提高.较高的入纤功率不仅会在光纤中引起各种非线性效应,对光脉冲的传输产生影响,也会对光纤本身的可靠性产生影响,为此介绍了高入纤功率对光纤系统的影响,分析了其产生的机理,并提出了应对措施.