Modeling and Experiments of the Gain and Noise Figure for an Irradiated Erbium-Ytterbium Co-Doped Fiber Amplifier

It is crucial to study the effect of radiation on the fiber amplifier devices. In the present paper, the Erbium-ytterbium co-doped fiber amplifier (EYDFA) has been irradiated by a neutron beam of different doses for various exposure times from an Am-241/Be-9 neutron source. The gain and noise figure of the EYDFA have been calculated theoretically and recorded after and before the irradiation to test its performance under the effect of irradiation. In order to show the enhancement in the gain of the fiber amplifier devices, a comparison between the gain of the irradiated EYDFA and Erbium doped Fiber amplifier (EDFA) has been carried out. The calculated results by the proposed model are in good agreement with the experimental ones. It indicates that the gain of EYDFA deteriorates after being irradiated by a neutron dose. Moreover, the gain of irradiated EYDFA has been reduced to 13.8 dB at a dose of 720 Gy.

Erbium Doped Fiber Laser and Amplifier

In this paper, new configuration is proposed, investigated and analyzed. Fiber laser and fiber amplifier are merged in one configuration which called Erbium Doped Fiber Laser and Amplifier (EDFLA) or integrating EDFL and EDFA in one design. The configuration has three main outputs;one for laser, second for amplifier and the third it can be used for on/off output. A surprising phenomenon was remarked during the operation of this configuration. The amplification is abolished during the lasing state and appeared again if the lasing is stopped or the switch is off. The difference between outputs with the lasing and without lasing has 30 dB EDFA gain value;it is a good sign that this optical configuration can be used as an on/off integrated optical device for fiber laser.

Transient Dynamics of Fluoride-Based High Concentration Erbium/Cerium Co-Doped Fiber Amplifier

We designed and evaluated a fluoride-based high concentration erbium/ cerium co-doped fiber amplifier. It is suitable for Metropolitan Area Networks due to faster transient, flatter (unfiltered) gain, smaller footprint and gain excursion than its silica-based counterpart.

High gain optical amplification and lasing performance of the Bi/P co-doped silica fiber in the O-band

In this Letter,the optical amplification characteristics of the home-made Bi/P co-doped silica fiber were systematically explored in the range of 1270–1360 nm.The maximum gain of 24.6 dB was obtained in the single-pass amplification device,and then improved to 38.3 dB in the double-pass amplification device for-30 dBm signal power.In addition,we simultaneously investigated the laser performance of the fiber with the linear cavity.A slope efficiency of 16.4%at~1313 nm was obtained with a maximum output power of about 133 mW under the input pump power of 869 mW at 1240 nm.As far as we know,it is the first laser reported based on the bismuth-doped fiber in China.

All-fiber cascaded ytterbium-doped nanosecond pulsed amplifier

A cascaded ytterbium-doped all-fiber master oscillator power amplifier（MOPA） with 1064-nm pulsed laser is demonstrated,and it can produce up to 20-W average power and 0.1-mJ pulse energy at tunable repetition rates from 10 to 200 kHz.Two main difficulties of the all-fiber configuration are overcome：all fiber isolator and mode field adapter between single mode fiber（SMF） and double cladding fiber（DCF）. Gain saturation and nonlinear effect are analyzed theoretically,and the possibility of further power-scaling of this cascade scheme is predicted.

Theoretical study on erbium ytterbium co-doped super-fluorescent fiber source

Erbium ytterbium co-doped super-fluorescent fiber source （EYD-SFS） has been simulated by a theoret- ical model based on rate equations and power transfer equations. The output performances of four basic structures of EYD-SFS have been expressed, and it indicated that the DPF structure is a preferable structure. The dependence of output power, mean wavelength and bandwidth stability on the pump fiber length and the concentration of Er3＋ and Yb3＋ have also been studied. The results indicated with a proper doping concentration of Er3＋ and Yb3＋ of 6.0 × 10^26 ions/m3 and 1.0 × 10^27 ions/m3, the optimal gain fiber length is 3.6 cm. In this condition, good performances of DPF structure of EYD-SFS have been achieved.

基于915 nm泵浦的铒镱共掺双包层光纤放大器

搭建了级联光纤放大系统,掺铒光纤放大器(EDFA)作为预放大级,铒镱共掺双包层光纤放大器作为功率放大级。为了提高镱离子吸收效率,实现功率稳定输出,功率放大级选择915 nm的半导体激光器作为泵浦源,铒镱共掺双包层光纤作为增益介质,采用前向泵浦的方式,对可调谐光源输入的1540~1565 nm波段的信号光进行了放大。在信号光功率为10 mW,预放大级泵浦功率为500 mW的条件下,对不同波长的信号光经过级联光纤放大系统进行了放大,最终在1565 nm处获得1.106 W的最高输出功率。

Tunable Multi Wavelength by Pulse Signal Modulation in Laser Pumping of EDFA

This report is aimed to present the result of experimental setup of the erbium-doped fiber amplifier (EDFA) with modulated pulse signal by laser pumping at wavelength 980 nm. The amplified spontaneous emission (ASE) from EDFA has multi wavelength and the spacing of wavelength can be controlled by controlling the pulse width of laser pumping. The result in this experiment shows that the feasibility of using EDFA system can generate the multi wavelength of all of C-Band spectrum. The pulse signal, for modulated laser pumping, is observed ranging from 10 to 100 Hz and the wavelength spacing can be tuned from 14.7 nm to 14.9 nm.

小型化抗辐照EDFA研究

为了研制面向卫星激光通信的小型化抗辐照掺铒光纤放大器(EDFA),介绍了掺铒光纤(EDF)在辐照环境下的失效机理,研究了不同掺铒浓度EDF的辐照性能,对比了不同材料复合屏蔽结构的抗幅照性能,最终实现了一种尺寸为60 mm×60 mm×15 mm、输出功率超过23 dBm和在20 krad(SI)辐照剂量下输出功率波动幅度低于0.1 dB的高性能小型化抗辐照EDFA。

Investigation of clustering effects on erbium-doped fiber laser performance

To design a compact erbium-doped fiber laser, a high-concentration erbium-doped fiber （EDF） is needed. However, increasing the erbium ion （Er3＋） concentration can reduce the EDF performance via the Er3＋-Er3＋ interaction. In this Letter, we investigate the Er3＋-Er3＋ interaction effect by designing a tunable erbium-doped fiberring laser （EDFRL）. This is the first time （to the best of our knowledge） that someone has considered different numbers of ions per cluster and simulated the EDFRL output power degradation due to ion-ion interaction. If the number of ions in the cluster is increased, the lasing output power will decrease accordingly. The most dom- inant effect is seen in the 1530 nm wavelength region, where the EDF shows a higher signal absorption compared to the other wavelength region. Moreover, a comparison has been done for lasing performance analysis with different dopant ion concentrations. The comparison results show that a higher dopant concentration is advanta- geous for longer-wavelength lasing.

本振光功率锁定方法应用于激光外差辐射计的研究

激光外差辐射计具备成本低、体积小、光谱分辨率高等优势,可扩展现有的地面碳测量网络,验证卫星观测结果,并能在卫星观测区域外提供数据覆盖.本文在现有的激光外差辐射计的基础上,报道了基于掺铒光纤放大器的可实现本振光功率锁定的近红外激光外差辐射计原型机.该激光外差辐射计利用一个中心波长为1.603μm的分布反馈式半导体激光器作为本振光源,采用掺铒光纤放大器放大本振光功率,并利用自动功率控制电路实现掺铒光纤放大器输出端光功率的锁定,消除了由本振光功率变化引起的基线斜率,从而实现免基线拟合的整层大气透过率谱的测量.详细评估了基于掺铒光纤放大器的高度集成化的激光外差辐射计的仪器性能,并在合肥市科学岛(31.9°N, 117.2°E)地区进行了整层大气CO_(2)透过率谱的测量.在一天的测量时间内得到6组大气CO_(2)透过率谱,与大气辐射模型模拟结果进行比对,测量结果一致.实验结果表明,掺铒光纤放大器的应用可以提高激光外差辐射计的性能,优化其结构,进而为实现无人值守的长期大气CO_(2)浓度观测和构建全面的碳观测网络提供仪器设备的补充.

高功率掺镱双包层光纤放大器放大特性理论模拟

运用掺镱双包层光纤放大器的理论模型,分析了连续和脉冲光放大时放大自发辐射(ASE)的计算方法。采用Runge-Kutta方法求解了考虑ASE稳态时掺镱双包层光纤放大器的放大特性,采用有限差分法求解了矩形、高斯和超高斯脉冲的放大特性。结果表明:用3 m长的双包层光纤、10 W的泵浦功率可以将脉宽3 ns、峰值功率为1 W的脉冲信号光峰值功率放大到15 kW左右;在饱和增益情况下,脉冲的波形变尖,宽度变窄;采用短的大模场双包层光纤和后向泵浦方式可以有效地降低ASE,并避免有害非线性效应。

高功率单模Er^(3+)∶Yb^(3+)共掺双包层光纤激光器

给出了单模输出的铒镱共掺双包层光纤激光器(EYDCFL)的数值分析及最新实验结果.基于速率方程及功率传输方程,对单模EYDCFL进行数值分析,从理论上对其性能进行优化.然后,在相同条件下进行了EYDCFL的实验研究.描述了输出激光功率随入纤泵浦功率和光纤长度的变化以及输出激光波长随光纤长度的变化.在光纤长度为6.3m时,获得了波长为1566nm、最大功率为2.2W的单模激光输出,整体光-光转换效率22%,这是目前国内用该类光纤获得的最高单模输出功率.

双包层Er^(3+)/Yb^(3+)共掺光纤放大器粒子数特性分析

基于速率方程和光传输方程 ,对双包层Er3 + /Yb3 + 共掺光纤放大器的计算模型进行了讨论 ,并利用数值模拟结果对 980nm激光抽运双包层Er3 + /Yb3 + 共掺光纤放大器Er3 + 上能级粒子数的分布特性进行了分析。分别给出了正向抽运和反向抽运条件下 ,Er3 + 归一化上能级粒子数分布曲线。

高速率空间激光通信系统及其应用

经过二十余年的快速发展,空间激光通信的研究重心逐渐从高精度ATP分系统向高速率通信分系统转移。紧密跟踪空间激光通信的国际发展最新动态,从通信带宽和链路功率两个方面,针对通信发射单元、接收单元和信道特性,分析了提高空间激光通信传输速率的技术难度与途径,分别阐述了波长1 550 nm、基于EDFA功放和前放技术,空间相干技术,光偏振复用技术,光波分复用技术的基本原理、性能指标及关键技术,为高速率空间激光通信提供了技术参考。

基于MOPA结构的1120nm掺Yb光纤放大器

基于主振荡功率放大器,采用1120nm光纤激光器作为种子激光,将其注入20m大模场面积单模双包层掺Yb光纤放大器,并用976nm半导体激光器泵浦实现了1 120nm信号光输出.实验中将注入种子激光功率预设为10mW,当半导体激光器泵浦功率增大至1.5 W时,放大器系统开始输出1 120nm信号光.当泵浦功率低于3.4W时,信号光功率随泵浦功率缓慢增长,系统斜率效率较低;而当泵浦功率高于3.4W时,信号光功率随泵浦功率线性增长,斜率效率明显增大,达到48.5%.限于最大注入泵浦功率为6.8W,放大器输出最高1 120nm信号光功率为1.97W,总的光-光转化效率为29%.输出信号光中心波长为1 120.89nm,线宽为0.02nm,极好地保持了种子激光的特性.结合实验情况,利用双包层光纤放大器的稳态理论模型,采用有限差分方法模拟了放大器输出信号光功率随泵浦光功率的变化曲线,结果显示理论模拟所得变化趋势与实验结果吻合良好,系统将在泵浦功率达到200W左右时达到饱和状态,说明目前光纤放大器系统具有很大的功率提升空间.

高功率多模铒镱共掺双包层光纤激光器的研究

为了获得尽可能高的输出功率以满足应用需求,分别以实验和数值分析的方法对铒镱共掺双包层光纤激光器的性能进行了进一步研究。实验上,采用加拿大国家光学研究所生产的EY805型铒镱共掺双包层多模光纤作为增益介质,描述了输出功率随入纤抽运功率以及光纤长度的变化,在光纤长度为1.8m的情况下,获得了3.5W的最大输出功率,光-光转换效率达31.8%。基于速率和传输方程,对该铒镱共掺双包层光纤激光器进行了数值模拟,在相同光纤长度下,计算的最大输出功率约4.4W,光-光转换效率40%,比实验结果要高。讨论了进一步对该光纤激光器性能进行优化的措施。该结果对于促进铒镱共掺双包层光纤激光器的实用化及其性能改进具有重要意义。

Er^(3+)/Yb^(3+)共掺双包层光纤的高功率L-band光纤激光器的实验研究

采用端面泵浦的方式,用尾纤输出波长为976 nm的高亮度多模半导体激光器,包层泵浦的铒镱共掺双包层大模面积光纤,非球面镜组耦合系统,进行了共掺双包层光纤的高功率L-band光纤激光器的研究,泵浦耦合效率达到了62%以上,并在F-P激光振荡腔中实现了高效的连续激光输出。在光纤长度为30 m、入纤功率为13.41 W时,首次报道输出连续功率达到了4.3 W。激光器的斜率效率为44%,激光输出中心波长1 603 nm。

使用FBG及更短光纤的高效Er^(3+)Yb^(3+)共掺双包层光纤放大器(英文)

提出在光纤放大器中 ,使用光纤布喇格光栅作为泵浦光反射镜 ,所需的双包层光纤可以缩短 ,同时至少保持了与没有光纤布喇格光栅作为反射镜时光纤放大器相同的性能 基于速率及传输方程 ,对使用和不使用光纤布喇格光栅的铒、镱共掺双包层光纤放大器的性能进行了数值模拟 结果表明 ,使用光纤布喇格光栅作为反射镜时光纤放大器可以获得与无光栅时相同的输出功率 ,但仅仅需要后者长度一半的光纤 ,无论是前向泵浦还是后向泵浦 对后向泵浦方式并使用光纤布喇格光栅作为反射镜 ,可获得最高的输出功率及光增益 。

被动锁模掺铒光纤激光器中的有理数谐波锁模

为了获得稳定的谐波锁模脉冲,分析了有理数谐波锁模的理论和非线性放大环镜的传输特性。构建了包括一个外部环和一个内部环的8字形被动锁模掺铒脉冲光纤激光器,对被动锁模掺铒光纤激光器进行了相关理论分析和实验研究。实验发现,当调整泵浦功率分别为167,146和126mW时,除了观测到了稳定的谐波锁模脉冲外,还观察到了分别类似于3阶、5阶、6阶的有理数谐波锁模脉冲产生现象,分析其脉冲重复频率,证实此类脉冲序列具有属于3阶、5阶和6阶有理数谐波锁模脉冲序列重复频率的一样的规律,认为其产生原因是8字形光纤激光器中的Sagnac环起了和主动锁模中调制器一样的作用。