Design and Compact Modeling of Saturated Erbium-Doped Fiber Amplifiers with Nonconfined Doping

We present a theoretical and experimental study of erbium-doped fiber amplifiers in saturated operation, examining designs in which erbium doping is distributed throughout the core. We show the penalty due to reduced inversion near the core boundary is negligible, while the reduced amplifier length can improve performance. We examine the accuracy of compact models for such nonconfined doping and show that a widely-used compact model exhibits substantial errors, while the Giles–Desurvire (G-D) model (1991, IEEE J. Lightwave Technol.9, 271) is accurate, despite having been derived for confined erbium doping. Furthermore, we simplify the G-D model by eliminating the saturation parameters and argue that this can improve accuracy. Finally, we experimentally validate the simplified G-D model for a moderately confined fiber, comparing amplifier measurements with predictions based on measured fiber parameters; measured and modeled gain and noise figure are in excellent agreement, in the absence of adjustable parameters.     

An Explicit Analytical Solution for the Transcendental Equation Describing Saturated Erbium-Doped Fiber Amplifiers

Analytical modeling of erbium-doped fiber amplifiers (EDFA) in all operating regimes (i.e., small-signal, signal-saturated, self-saturated, uni- or bidirectionally pumped) requires solving a transcendental equation derived by Saleh et al. in 1990. In this paper, we describe an approximate, although accurate, explicit analytical solution for such a transcendental equation. The use of this explicit solution alleviates computational time constraints and should therefore permit extensive multidimensional or parametric studies of EDFAs. It could be advantageously applied to the study of multiwavelength amplified network systems, with new potentials for interactive computer-assisted design.     

Simulation Performance of Erbium-Doped Fiber Amplifiers

In this paper, a simple approach is introduced to simulate the main performance of erbium-doped fiber amplifiers by using two empirical formulas to calculate saturated gain and corresponding noise figure. Then conflict equations are presented to improve this approach. At the end of the paper the comparison of calculation results before and after improvement is given. It has been shown to be more accurate.     

掺铒光纤放大器（EDFA）简化模型

从掺铒光纤放大器的能级速率方程和光传输方程出发，得到一个简单的表达式，可用来计算放大器的增益、噪声系数等。在放大器的非饱和范围内，计算结果和实验结果十分一致。     

掺铒光纤放大器的动态增益均衡

波分复用系统对掺铒光纤放大器增益的动态平坦提出了严格的要求,为此人们设计了各种动态增益均衡器以实现EDFA的增益谱的平坦化。现有的各种动态增益均衡技术分静态和动态两种。我们讨论了几种不同类型的动态增益均衡方法,详细并举例分析几种典型的动态增益均衡器基本结构、工作原理、适用范围及其优缺点。最后对未来动态增益均衡器的发展作了展望。     

多波长掺铒光纤激光器的研究进展

多波长掺铒光纤激光器(MW-EDFL)在密集波分复用(DWDM)系统中具有重要作用,是近年来光纤通信领域的研究热点。回顾了多波长掺铒光纤激光器的发展历史,介绍了多波长掺铒光纤激光器的工作原理,包括其抑制模式竞争、实现多波长输出的方式,着重介绍了多种梳状滤波器的原理,包括Lyot滤波器、Sagnac干涉环、MachZehnder干涉仪。综述了近年来实现多波长掺铒光纤激光器的研究成果,分析了各个实现方案的优劣特性,并对其应用和发展前景进行了展望。     

分布式掺铒光纤放大器的理论分析

给出了一种分析分布式掺铒光纤放大器的理论方法，可以对放大器的信号增益和泵浦吸收进行分析，并能够为分布式掺铒光纤放大器的设计提供理论依据。通过推导得出了基本公式，并就一些特殊情况作了讨论。该方法适用于１４８０ｎｍ和９８０ｎｍ泵浦的放大器系统。     

基于石墨烯的被动锁模掺铒光纤孤子激光器

报道了石墨烯作为可饱和吸收体的被动锁模掺铒光纤孤子激光器。采用环形腔结构,在抽运功率为370.4mW时,产生了重复率为3.16MHz,脉宽约为1.32ps,平均输出功率为1.07mW的锁模脉冲,其单脉冲能量为0.338nJ,并观察到激光中心波长在1556.72～1558.76nm之间可调。基于Ginzburg-Landau方程进行了数值模拟,得到的结果和实验一致。     

Extended Black-Box Model for Fiber Length Variation of Erbium-Doped Fiber Amplifiers

Black-box models (BBMs) for erbium-doped amplification have been demonstrated to be a powerful tool. A new extended BBM including variations of the erbium-doped fiber length is presented for fiber length optimization in amplified systems. The comparisons with experimental results show a very high accuracy, with maximum discrepancies of about 0.5 dB.      

掺铒光纤放大器的理论分析：二能级近似

本文针对存在和不存在受激态吸收两种情况分别推导了当有多束光在掺铒光纤中传播时掺铒光纤放大器的速率方程组，并通过合理的近似交过些方程转换成二能级模型下的一组方程。对１４８０ｎｍ泵浦的掺铒光纤放大器进行了研究。理论分析结果与实验结果一致。     

Reduction of Soliton Interaction in Distributed Erbium-Doped Fiber Amplifiers

Methods of reducing the soliton interaction in distributed erbium-doped fiber amplifiers have been studied. The results show: if the optical phase conjugation is applied in proper periodic length, input relative phase between two solitons, and non-equal amplitude input is chosen, the soliton-soliton interaction and soliton self frequency shift can be deleted effectively.     

掺杂稀土光纤激光器与激光放大器(续篇)

(1)美国贝尔做出的光纤放大器实验。掺铒光纤,芯径:5μm,数值孔径:0.18,掺杂:1.8×10~(18)铒离子/cm~3,泵光吸收为2.5dB/m,信光吸收为4dB/m,输入光信号为15μW(1.53μm),泵光功率为20、55、100mW(0.52μm)。由此得到的室温下增益为22dB。20mW泵浦时最佳长度为7.5m(增益为10dB)。图14是得到的主要测量曲线,从中不难看出,在高功率泵浦时,增益将出现饱和。     

基于光纤环形镜的L-波段掺铒光纤放大器增益的提高

提出了一种基于光纤环形镜作为反射器的反射式L-波段掺铒光纤放大器(EDFA)结构。光纤环形镜不但可以反射后向放大自发辐射(ASE)作为二次抽运源，而且还可以反射信号，使信号得到二次放大。当抽运功率为115mW时。在1570～1605nm波长范围内，反射式L-波段掺铒光纤放大器的平坦小信号增益达到29．14dB，与前向抽运方式L-波段掺铒光纤放大器相比(保持平坦性不变)。增益提高了5．33dB。分别输入波长为1580nm和1600nm的信号，反射式L-波段掺铒光纤放大器的饱和输出功率为7．63和7．6dBm．与前向抽运方式L-波段掺铒光纤放大器相比分别提高了2．98和3dB。     

Theoretical Investigation of the Gain Profile of Erbium-Doped Fiber Amplifiers

An exact analytical expression for the gain profile of erbium-doped fiber amplifiers (EDFAs) is presented. It is shown theoretically that the shape of the gain profile of an EDFA is determined by the average gain per unit fiber length. It turns out that the optimum fiber length for minimum gain differences in an arbitrary bandwidth is exactly proportional to the desired gain and to the achieved gain differences. Furthermore it is shown that an erbium-doped fiber with a special wavelength-dependent fiber background loss produces a flat gain profile for any desired gain if the optimum fiber length is chosen. An analytical expression for the required background loss is given.     

掺Yb3+光纤激光器及放大器

介绍掺Ｙｂ＾３＋光纤激光器及放大器的原理、研究进展及发展潜力,并对掺Ｙｂ＾３＋光纤的超短脉冲激光及其放大技术做一介绍。文中还介绍了我们研制的掺Ｙｂ＾３＋石英单模光纤     

多路放大系统的增益均衡

研究了铒光纤长度对多路波分复用放大系统性能的影响。计算结果表明，选择适当的铒光纤长度能够有效地减小多路放大系统的增益偏差，实现均衡放大。     

一种分析掺铒光纤放大器性能的简单方法

掺铒光纤放大器的主要性能是它的饱和增益特性和噪声系数。本文首先用两个经验公式，介绍了一种用于模拟掺铒光纤放大器性能的简单方法，接着给出了一个超定方程组，对这种方法作了进一步的改进，最后分别给出利用改进前后的方法计算所得到的结果，同时对计算结果和测量数据作了比较，比较显示我们的方法有着更高的精度。     

Multiwavelength Operation of Erbium-Doped Fiber Lasers by Periodic Filtering and Phase Modulation

This paper explains the principles behind multiwavelength operation of an erbium-doped fiber laser (EDFL) under the combined effect of cavity phase modulation and periodic wavelength filtering. A mathematical model is developed to simulate the behaviour of the multiwavelength EDFL, both in time and frequency domains. The effects of various parameters such as pump power, filter channel spacing, modulation index and frequency are observed and explained. An all-fiber EDFL was constructed, using a piezo-transducer-based phase modulator and a Sagnac loop periodic filter, to validate the theoretical results. The effects of pump power, modulation frequency and modulation index were monitored experimentally, justifying the theoretical explanation. The multiwavelength EDFL has several potential applications in fiber sensing due to its flexible all-fiber design.     

基于氧化石墨烯被动锁模的窄线宽皮秒脉冲掺铒光纤激光器

报道了用氧化石墨烯作为可饱和吸收体的全光纤结构皮秒脉冲掺铒光纤激光器。该激光器的线形谐振腔由窄带的光纤布拉格光栅和氧化石墨烯可饱和吸收镜构成。当抽运功率为22mW时,实现了稳定的重复频率为5.82MHz的锁模激光脉冲输出,脉宽为87ps,光谱中心波长为1549.3nm,3dB谱宽为0.06nm,信噪比为66dB。     

Passive Q-Switching and Mode-Locking of Erbium-Doped Fluoride Fiber Lasers at 2.7 μm

Passive Q-switched and mode-locked operation of a 2.7-μm fluorozirconate fiber laser is reported. Both mode-locking and Q-switching were attained by means of InAs epilayers used as saturable absorbers. Another technique used was the so-called flying-mirror mode-locking, whereby an external resonator with a vibrating mirror is coupled to the active fiber resonator. Both techniques yielded Q-switched pulses containing trains of mode-locked pulses with durations shorter than 2.5 ns—the resolution limit of the detection unit.