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为了探讨多级级联掺镱光纤放大器的脉冲放大特性,采用主振功率放大技术(MOPA),实验研究了3级级联、全光纤结构的高增益脉冲激光放大器。通过优化各放大级增益光纤的长度和抽运光功率的大小,在保证高放大增益的同时,抑制了掺镱光纤中自发辐射光的自生激光振荡,并对第2放大级进行了结构优化。在脉冲激光放大过程中实现了中心波长1064nm、脉冲宽度19ns、重复频率5kHz、峰值功率3.8kW、总放大增益达43.8dB的稳定激光输出。同时,制作完成了1台结构紧凑、全光纤结构的脉冲光纤放大器样机,对重复频率1Hz的低频脉冲信号进行了放大实验,也得到了43.2dB的输出信号增益。结果表明,本脉冲光纤放大器对低频脉冲信号有很好的放大效果。 相似文献
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基于速率方程理论对低重复频率高功率脉冲抽运Er-Yb共掺光纤放大器(EYDFA)进行了理论研究。通过采用有限差分法对理论模型的求解,系统分析了在放大自发辐射(ASE)受限情况下,抽运脉冲峰值功率、抽运脉宽、信号时延对放大器性能的影响。结果表明,在将ASE控制在合理范围的情况下,抽运脉冲存在一个最佳的抽运脉冲宽度,信号脉冲相对抽运脉冲的时延对输出峰值功率和脉冲能量有非常重要的影响。而且对给定的增益介质,抽运脉冲峰值功率也并非越高越好,而是存在一个最佳值。该研究结果对高功率脉冲抽运Er-Yb共掺光纤放大器的实验研究具有指导意义。 相似文献
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为了简单、快捷地模拟掺镱双包层光纤放大器的脉冲放大特性,采用有限元软件FEMLAB模拟掺Yb3+双包层光纤放大器的脉冲放大特性。用与快速傅里叶法模拟Yb3+光纤放大器脉冲放大特性相同的参量计算了在915nm前向抽运下,光纤放大器中的上能级粒子数,抽运光和放大自发辐射在光纤中的稳态分布,以及高斯脉冲和方波脉冲的输出、能量及增益特性,得到的与快速傅里叶法模拟的一致的粒子分布图等特征图,而且比快速傅里叶法得到更多和更准确的结果。结果表明,应用FEMLAB只需根据掺Yb3+光纤放大器的方程组,可以方便、快捷地确定参数进行数值模拟,对掺镱光纤放大器的系统设计和参量优化具有很好的参考价值。 相似文献
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1053 nm掺Yb3+双包层光纤放大器脉冲放大特性研究 总被引:2,自引:1,他引:2
从掺Yb^3+光纤放大器(YDFA)的功率传输方程出发,采用有限差分法对掺Yb^3+双包层光纤放大器在1053nm的脉冲放大特性进行数值分析。模拟计算了在977nm前向抽运下,光纤放大器中的上能级粒子数,抽运光和放大自发辐射(ASE)在光纤中的稳态分布。分析了掺Yb^3+双包层光纤放大器的单脉冲波形畸变以及控制输入脉冲形状来产生需要的超高斯输出脉冲形状。讨论了最佳长度以及抽运方式差别等问题。 相似文献
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低重复频率脉冲掺镱光纤放大器 总被引:1,自引:0,他引:1
为了研究低重复频率两级脉冲掺Yb3+光纤放大器,采用脉冲信号驱动的半导体激光器作为种子光源,产生重频100Hz、半峰全宽100ns、能量30nJ的矩形光脉冲。第1级放大采用单模掺Yb3+光纤放大器,双程放大方案有效地抑制了放大自发辐射,放大后的脉冲能量达到了8.2μJ。第2级放大采用纤芯直径15μm的双包层掺Yb3+光纤放大器,大功率多模半导体激光器连续抽运。结果在抽运功率为7.3W时,放大输出脉冲能量达到了242μJ,放大输出半峰全宽压缩为29ns。输出的光束质量较好,为准单模输出。结果表明,该光纤放大器输出脉冲能量高,具有全光纤化、结构简单的特点。 相似文献
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为了研究不同增益光纤长度下1555nm高功率光纤放大器的输出功率,采用两级混合结构的方法,用掺铒光纤放大器和双包层铒镱共掺光纤放大器分别作为1级预放大器和2级主放大器。掺铒光纤放大器对信号光进行预放大,并提高放大器的信噪比;双包层铒镱共掺光纤放大器为主放大器,其双包层结构可以把更多的多模抽运光耦合进系统。对铒镱共掺光纤的最佳长度做了理论分析和实验验证,在信号光功率为10mW、掺铒光纤放大器的抽运功率为318.58mW、双包层铒镱共掺光纤放大器的抽运功率为11.71W、增益光纤长度为14m时,输出功率取得了2.11W的实验数据。在分析输出信号光谱时发现,L波段附近有放大自发辐射谱出现,这是选择的增益光纤过长导致的。结果表明,在光功率和信号光功率一定时,光纤放大器有一个最佳的光纤长度。这一结果对研究光纤放大器的高功率输出是有帮助的。 相似文献
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全光纤高功率Er/Yb共掺双包层光纤放大器 总被引:2,自引:0,他引:2
结合Er/Yb共掺双包层光纤(EYDCF)和丰振荡功率放大(MOPA)技术,采用高功率多模抽运方式设计和实验研究了全光纤化两级放大器.分析了放大器的各种性能参数;1550 nm连续光放大得到最大斜率效率为29%,最大输出功率1.52 W,功率稳定度0.4%;2 kHz脉冲放大时得到最大输出功率1.1 W,功率稳定度0.45%,最大斜率效率25%.并从放大后光谱和时域波形分析了导致脉冲放大时斜率效率和功率转换效率较低的主要原因为Yb3+离子波段放大自发辐射(ASE)的出现和Er离子波段ASE的过多积累.在高功率放大时,增益随输入信号功率增大迅速下降;同时结合抽运光频谱随驱动电流变化分析了其对放大器性能的影响. 相似文献
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为了研究自发辐射对高功率铒镱共掺脉冲光纤放大器性能的影响,在速率方程理论的基础上,采用有限差分法对理论模型进行了数值求解。对不同抽运、信号和光纤参量配置情况下,自发辐射对放大器性能的影响进行了模拟分析。结果表明,由于自发辐射自饱和的限制,在其它条件相同的情况下,为了得到最高的单脉冲能量和峰值功率,放大器输入信号存在一个最佳的重复频率,且该最佳重复频率与抽运功率成正比与脉冲宽度成反比。研究结果对高功率铒镱共掺光纤脉冲放大器的设计和实验研究有重要指导意义。 相似文献
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高功率脉冲Er-Yb共掺光纤放大器中放大自发辐射的抑制方法 总被引:2,自引:1,他引:1
为了研究放大的自发辐射(ASE)对高功率脉冲Er-Yb共掺光纤放大器(EYDFA)的影响,采用数值模拟对EYDFA中不同参数信号的放大进行了研究。结果表明,Yb波段(1.0~1.1μm)ASE是制约放大器输出功率提升的主要因素。因此,有效地抑制Yb波段ASE将有助于放大器性能的提高。通过进一步研究发现,在放大器的抽运端引入一个Yb波段的辅助信号能有效地抑制Yb波段ASE,从而提高抽运转换效率,提升放大器的输出功率。 相似文献
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工作在2μm波段的脉冲掺铥光纤激光器,可望在遥感探测、相干雷达、空间光通信、激光医疗和特种材料加工等领域获得重要应用。目前,利用波长在1.55μm附近的脉冲掺铒光纤激光器作泵浦源的增益开关掺铥光纤激光器是实现全光纤结构纳秒脉冲掺铥光纤激光器的理想方式之一。采用实验研发的纳秒脉冲掺铒激光器作种子源,研制了全光纤MOPA(masteroscillator power amplifier)结构的纳秒脉冲掺铒光纤激光器,输出波长1 547 nm,脉冲频率100 kHz,脉冲宽度50 ns,平均功率1 W,单脉冲能量10μJ。使用该脉冲掺铒光纤激光器抽运掺铥光纤,实现了波长1 963 nm的增益开关脉冲激光输出。该掺铥光纤激光器为全光纤结构,重复频率100 kHz,最小脉宽47 ns,最大单脉冲能量100 nJ。激光输出稳定可靠,更高的单脉冲能量,平均功率和峰值功率可由进一步级联光纤放大器实现。 相似文献
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Ranaud C.C. Offerhaus H.L. Alvarez-Chavez J.A. Nilsson C.J. Clarkson W.A. Turner P.W. Richardson D.J. Grudinin A.B. 《Quantum Electronics, IEEE Journal of》2001,37(2):199-206
We theoretically and experimentally analyze Q-switched cladding pumped ytterbium-doped fiber lasers designed for high pulse energies. We compare the extractable energy from two high-energy fiber designs: (1) single- or few-moded low-NA large mode area (LMA) fibers and (2) large-core multimode fibers, which may incorporate a fiber taper for brightness enhancement. Our results show that the pulse energy is proportional to the effective core area and, therefore, LMA fibers and multimode fibers of comparable core size give comparable results. However, the energy storage in multimode fibers is mostly limited by strong losses due to amplified spontaneous emission (ASE) or even spurious lasing between pulses. The ASE power increases with the number of modes in a fiber. Furthermore, spurious feedback is more difficult to suppress with a higher NA, and Rayleigh back-scattering increases with higher NA, too. These effects are smaller in low-NA LMA fibers, allowing for somewhat higher energy storage. For the LMA fibers, we found that facet damage was a more severe restriction than ASE losses or spurious lasing. With a modified laser cavity, we could avoid facet damage in the LMA fiber, and reached output pulse energies as high as 2.3 mJ, limited by ASE. Theoretical estimates suggest that output pulse energies around 10 mJ are feasible with a larger core fiber, while maintaining a good beam quality 相似文献
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In this paper, we investigate the effects of complex energy transfer dynamics and Gaussian profiles on the gain and noise figure performance of erbium-doped fiber amplifiers (EDFAs) with high doping concentration. We use a two-level system to study the complex energy transfer dynamics that comes from the homogeneous up-conversion (HUC) and the pair-induced quenching (PIQ). In our model, the system is stimulated by a pump source at the wavelength of 1480 nm and operated with a signal source at the wavelength of 1560 nm. Assuming a uniform distribution of erbium ions in the fiber core, we approximate the fundamental mode distributions by Gaussian profiles which are commonly used to calculate the mode radius or spot size. Using the numerical calculations and analysis of the rate and power propagation equations for a two-level model under consideration, the most advantageous Gaussian profile is determined as the Whitley mode radius to obtain a high-gain and a low-noise figure per unit length of silica-based fiber amplifiers. The effects of the number of ions per cluster and the percentage of ions in clusters on the calculated gain and noise figure are compared for several pump powers. Results are discussed to achieve a desired gain and noise figure performance, and compared with the available experimental data to verify the feasibility of the model. 相似文献
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Characterization and modeling of amplified spontaneous emission in unsaturated erbium-doped fiber amplifiers 总被引:1,自引:0,他引:1
E. Desurvire M. Zirngibl H.M. Presby D. DiGiovanni 《Photonics Technology Letters, IEEE》1991,3(2):127-129
The generation of amplified spontaneous emission (ASE) in erbium-doped fiber amplifiers (EDFAs) is characterized. A theoretical model, leading to closed-form analytical expressions for the backward and forward ASE power spectra, is developed for the unsaturated gain regime. This study shows that for the unsaturated gain regime, both power and spectral distributions of the ASE can be well described through the closed-form expressions, which require only measurable experimental parameters.<> 相似文献
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提出了Er/Yb共掺的光纤放大器中,Yb离子仍然存在基态能级斯塔克(Stark)分裂的假设,考虑1060 nm波段辐射,利用速率方程和传输方程,结合Er/Yb共掺双包层光纤的吸收和发射系数谱,采用4阶龙格-库塔(Runge- Kutta)算法,建立了模拟Er/Yb共掺双包层光纤放大器放大自发辐射(ASE)光谱的理论模型。通过改变抽运功率和信号功率,对其前向放大自发辐射光谱特性进行了全面的分析。大信号入射时,改变抽运功率,只改变输出功率大小。输出光谱形状不变,而当信号功率足够小时,前向放大自发辐射光谱在1535 nm和1543 nm处会出现2个局部峰值,理论模拟与实验数据相符。 相似文献
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Pedersen B. Dybdal K. Hansen C.D. Bjarklev A. Povlsen J.H. Vendeltorp-Pommer H. Larsen C.C. 《Photonics Technology Letters, IEEE》1990,2(12):863-865
A full-scale numerical model for the erbium-doped fiber amplifier has been developed that incorporates realistic index and erbium-concentration profiles as well as the spectral distribution of amplified spontaneous emission (ASE). The high accuracy of the model is demonstrated by comparison with a comprehensive set of data, including gain, ASE, and pump power, obtained for a well-characterized Er-Al-doped fiber. An absorption-to-emission cross-section ratio of 1.0 was measured at the gain peak. Pumping at 654 nm, the excited state absorption was observed to be insignificant. A high gain of 39.6 dB was achieved in the experiment 相似文献