两段级联掺铒光纤放大器的优化研究

基于Giles模型,研究了980 nm和1480 nm泵浦的两段级联掺铒光纤放大器(EDFA)的设计,得出了掺铒光纤(EDF)的最佳长度和光隔离器的最佳位置随泵浦功率和信号功率的变化关系.比较980 nm和1480 nm泵浦的两段级联EDFA,可以发现,前者的最佳EDF长度短,而光隔离器最佳位置距EDFA输入端远.     

掺铒光纤放大器及其在光纤孤子通信系统中的应用

讨论掺铒光纤的制造技术和掺铒光纤放大器的放大原理。结果表明,掺铒光纤放大器非常适用亍光纤孤子通信系统对光孤子进行放大。     

掺铒光纤放大器在光通信中的应用

介绍掺铒光纤放大器（EDFA）的工作原理，基本结构及其在光通信中的应用。     

级联双包层铒镱共掺光纤放大器的性能分析

基于速率方程和光传输方程,对级联双包层铒镱共掺光纤放大器(Er3+/Yb3+ co-Doped Fiber Amplifier,EYDFA)进行了研究.数值模拟计算得到级联双包层EYDFA的最佳光纤长度,以及前后向泵浦功率之比和光隔离器位置对于增益以及噪音系数的影响.通过选择合适的前后向泵浦功率之比和隔离器的位置优化级联放大器结构,其增益提高了4 dB,噪音系数降低了近3 dB.     

智能化掺铒光纤放大器

介绍一种智能化的掺铒光纤放大器(EDFA)技术.基于掺铒光纤的光放大特性与EDFA内外部工作参量(如构成EDFA的元器件参量、泵浦激光参量、输入/输出光信号参量等)的关系,采用智能化处理技术使EDFA能按照外界条件,自动地调整自身工作状态,使之符合应用系统的需要.智能化掺铒光纤放大技术可以使EDFA的应用更灵活,既可用作前置放大,也可用作功率放大或线路放大,同时还带来一些新的特点和优越性能.实验制作的智能化EDFA可以在输入信号小到-40dBm或大到+10dBm即约50dB的宽动态范围内正常工作.     

级联双包层铒镱共掺光纤放大器的性能分析

基于速率方程和光传输方程,对级联双包层铒镱共掺光纤放大器（Er3+/Yb3+ co-Doped Fiber Amplifier,EYDFA）进行了研究.数值模拟计算得到级联双包层EYDFA的最佳光纤长度,以及前后向泵浦功率之比和光隔离器位置对于增益以及噪音系数的影响.通过选择合适的前后向泵浦功率之比和隔离器的位置优化级联放大器结构,其增益提高了4 dB,噪音系数降低了近3 dB.     

铋基掺铒光纤放大器中放大自发辐射处理研究

分别设计了一个带光隔离器和一个带光环形器的复合型宽带铋基掺铒光纤放大器(Bi-EDFA),理论上研究了Bi-EDFA中对于后向传输放大自发辐射(ASE)的处理对放大器性能的影响。研究表明,在C+L波段多波长信号同时输入情形下,通过在铋基掺铒光纤中插入一个光隔离器抑制后向传输的ASE,可以提高放大器各波长信号增益,降低噪声系数。利用一个光环形器引导后向传输的ASE去泵浦一段未抽运的低掺杂铋基掺铒光纤,可以显著地提高放大器长波段信号增益,而噪声系数只是略有增加,理论研究与报道的实验结果达到了比较好的一致。研究结果对于新型宽带Bi-EDFA的设计和应用具有一定实际指导意义。     

980nm泵浦的掺铒光纤放大器实验研究

10m长的铒掺杂光纤在980nm波长半导体激光器泵浦下,获得了对1.55μm波长的入射光信号的放大作用。当入射光信号功率为-22dBm而泵浦功率为9.3mW时,放大器的增益为15dB.     

掺铒光纤放大器中抽运问题的理论分析

依据掺铒光纤放大器的速率方程和光传输方程,在不计放大自发辐射的情况下,得出了抽运功率和信号增益在放大器中沿光纤分布的隐函形式的解析表达式,并利用数值模拟对三种抽运方式下的放大器特性进行了分析。     

石英基L波段扩展掺铒光纤及其放大性能

掺铒光纤放大器的增益带宽是限制光纤通信系统传输容量提升的重要因素.受铒离子激发态吸收所限,常规L波段掺铒光纤难以实现更长波段的带宽扩展.本文基于改进的化学气相沉积工艺成功制备了P/Al共掺石英基L波段扩展掺铒光纤,研究了共掺离子对于铒离子4I13/2能级到4I9/2能级激发态吸收的影响.通过分别搭建单级前向泵浦和多级的放大结构,测试了其宽带放大性能.基于前向980 nm泵浦的单级结构,当输入信号功率为–9 dBm,泵浦功率为530 mW时,该光纤在1625.3 nm处增益达10.5 dB,最大噪声指数为5.9 dB.多级放大结构下,该光纤在1625.3 nm处增益可达23.4 dB.实验结果表明P/Al共掺石英基掺铒光纤可以有效抑制铒离子的激发态吸收,为进一步扩展L波段增益带宽提供了强有力的可行方案.     

双波长全光自动增益箝制掺铒光纤放大器的实验研究

提出了结构简单的光纤布喇格光栅（FBG）双波长全光自动增益箝制方案,并进行了相关实验.结果表明,在三种不同的箝制波长组合1535.64nm+1562.68nm、1530.48nm+1562.68nm、1530.48 nm+1551.36 nm条件下,1540 nm信号的输出增益大小和输入信号功率动态范围几乎一致.对应此三种箝制波长组合,环路内的损耗分别为：14.7 dB、15 dB、15 dB.由此证明,在相同泵浦条件和环路损耗条件下,此三种不同箝制波长组合具有近似相同的箝制效果.而1551.36 nm+1562.68 nm箝制波长组合得到的结果相差甚远.此结果说明,在设计双波长全光自动增益箝制掺铒光纤放大器（OAGC-EDFA）时,为了取得足够大的信号增益,两箝制波长的波长间隔应尽量较大.     

Space radiation effect on EDFA for inter-satellite optical communication

The erbium-doped fiber (EDF) has been irradiated by electron with a dose of 1000 krad to analyse the space radiation effect on EDF amplifier (EDFA) in inter-satellite optical communication. This is the first work to analyse the effect on actually applied systems. Three critical parameters of EDFA, most important for external module subsystems, have been tested. The output power comes down to −57.21 dBm and the noise figure (NF) climbs up to 18.14 dB at dose 1000 krad, when the input power is −2.00 dBm. Although there is a strong ability to recover after the radiation experiment, EDFA deterioration is really huge. Apart from that, the central wavelength of EDFA never changes. To guarantee the accuracy of analysis of the radiation effect on EDFA, WDM coupler and isolator are also irradiated with the EDF at the same time. According to the results of all the tests, the EDFA could be directly used in the low-radiation dose orbits if doses are less than 20 krad. And the radiation experiment data will also be a good reference for the design of the actual systems in inter-satellite optical communication with different dose orbits.     

1480nm泵浦的掺饵光纤放大器上能级粒子数分布

本文建立了1480nm泵浦下掺饵光纤放大器的速率方程组,并利用这组方程对掺饵光纤放大器的上能级粒子数分布进行了数值分析,在同向泵浦、反向泵浦以及双向泵浦三种不同的泵浦方式下,会别给出了小信号(如,1μW)和大信号(如1mW)功率输入时掺饵光纤的上能级归一化粒子数分布曲线。     

Noise performance analysis of bi-directionally pumped distributed fiber Raman amplifiers with consideration of fiber nonlinearity and its impact on EDFA output OSNR

Under small-signal assumption, equivalent noise figure normalized by fiber nonlinearities (NENF) of bi-directionally pumped distributed fiber Raman amplifiers (BiDFRA) is derived. Amplified spontaneous Raman scattering noise and double Rayleigh scattering noise are both included. The relation between NENF and Raman gain, forward Raman gain percentage is investigated under different polarization factor and Rayleigh scattering coefficient. It agrees well with numerical simulation results. Based on the analytical expression, the optical signal-to-nose ratio (OSNR) improvement of hybrid pre-BiDFRA/erbium-doped fiber amplifier (EDFA) compared with sole EDFA is studied. It is shown that there is an optimum Raman gain and forward Raman gain percentage to maximize the OSNR improvement. Finally, some guidelines on BiDFRA design are proposed.     

L-band all-optical gain-clamped EDFA by utilizing C-band backward ASE

By using an optical circulator and C/L-band wavelength division multiplexer to recycle the C-band backward ASE, an L-band gain-clamped erbium-doped fiber amplifier is presented. We have experimentally studied the static gain clamping property of this amplifier. As the ASE feedback attenuation is set to 0, the gain at 1585 nm can be clamped at 18.84 ± 0.26 dB within dynamic range of 25 dB and the critical power reaches about −15.09 dBm. The gain variation and saturated output power at 1585 nm for 0 dB attenuation are 1 dB lower and 2.17 dB higher than those for 30 dB attenuation, which indicates that the L-band EDFA gain can be effectively clamped via the ASE injection technique.     

Double-pass erbium-doped zirconia fiber amplifier for wide-band and flat-gain operations

The double-pass erbium-doped zirconia fiber amplifier (EDZFA) is proposed and demonstrated to provide a wide-band amplification as well as flat-gain operation in both the C- and L-band regions using only a single-gain medium. The proposed amplifier utilizes an erbium-doped zirconia fiber (EDZF) with erbium ion concentration of 2800 ppm as a gain medium. The medium is fabricated in a ternary glass host, zirconia-yttria-aluminum codoped silica fiber through solution doping technique along with modified chemical vapor deposition (MCVD). Compared to a single-pass operation, the double-pass EDZFA shows a better gain performance. At input signal power of 0 dBm and the optimum EDZF length of 2 m, a flat gain of around 16 dB is achieved by the proposed double-pass amplifier with gain variation of approximately 2.5 dB throughout the wavelength range from 1530 to 1590 nm. However, the noise figure of the double-pass amplifier is slightly higher than that of the single-pass due to inefficient population inversion at the input part of the amplifier.     

L波段掺铒光纤放大器的自发辐射谱与增益的研究

利用Giles模型对L波段掺铒光纤放大器小信号增益特性进行了数值模拟,模拟结果表明最佳铒纤长度并不是一定值,它随输入信号波长的不同而改变,较短的波长对应较短的光纤长度;在数值模拟、分析的基础上,分别采用7m和9m的L波段铒光纤构成长波段掺铒光纤放大器,通过实验测量,分析比较了它们的自发辐射谱以及增益和噪声指数,得到了光纤长度对L波段增益谱、噪声指数和自发辐射谱的影响规律;最后,辅以C波段掺铒光纤放大器加以分析,指出了适合于放大L波段信号的最佳自发辐射谱型。     

级联放大光纤传输中的调制不稳定性

本文在考虑光纤损耗和级联放大器的情况下,推导出了调制不稳定性的产生条件和增益的普适解析表达式,并利用分立步傅里对数值方法对非线性传输进行了仿真,证明了本文的解析结论的正确性.     

Experimental and theoretical studies on a double-pass C-band bismuth-based erbium-doped fiber amplifier

Performance of a Bismuth-based Erbium-doped fiber amplifier is experimentally and theoretically investigated using 1480 nm pumping with double-pass scheme. In the theoretical analysis, the rate and power propagation equations are solved to examine the optimum length for the C-band operation as well as the gain and noise figure characteristics. The calculated small signal gain is 38 dB with gain variation of less than 3 dB. The measured gain is 4 dB lower due to spurious reflections which were ignored in the theoretical analysis. At input signal power of 0 dBm, a gain of 14.5 dB is obtained experimentally with gain variation of less than 1 dB within the wavelength region from 1530 to 1565 nm. The noise figure is less than 12 dB within this region.     

Gain optimization of an erbium-doped fiber amplifier and two-stage gain-flattened EDFA with 45 nm flat bandwidth in the L-band

An erbium-doped fiber amplifier (EDFA) is simulated. The variation of gain with different parameters is obtained and the values of these parameters are optimized to achieve a maximum value of gain. A two-stage gain-flattened EDFA consisting of two EDFAs in series is also simulated. In the operating range of 1565-1610 nm, the flat gain of 46 dB is obtained.