Analysis of Er-doped fiber laser stability by suppressing relaxation oscillation

For Er-doped fiber lasers, we show that the fluctuation of lasing power caused by resonant pump-power perturbations is inversely proportional to the lifetime of photon in the laser cavity. Analysis shows that Er-doped fibers with high-gain coefficient are favorable for fiber lasers in the view of point of suppressing the lasing-power instability caused by the resonant pump perturbation. The results obtained are especially useful for single-frequency Er-doped fiber lasers which have a very short cavity length, i.e., a short lifetime of photon in the cavity.     

泵浦调制光纤激光器中混沌产生和同步的研究

分析了泵浦调制掺铒光纤环形激光器中混沌产生以及同步的理论模型。构建了双环掺铒光纤环形激光器的实验系统。通过调节泵浦功率、调制频率和可调谐滤波器，可以产生不同波长的混沌信号，并实现混沌的同步。     

Influences of finite gain bandwidth on dissipative solitons in passively mode-locked Er-doped fiber laser

Dissipative solitons in the passively mode-locked fiber lasers based on the gain medium of erbium-doped (Er-doped) fiber have attracted a lot of interest in recent years. In this paper, we study the influences of finite gain bandwidth on dissipative solitons in passively mode-locked Er-doped fiber laser. We investigate the influences of the finite gain bandwidth on pulse duration, pulse peak power and single pulse energy of dissipative solitons. The results show that gain bandwidth of the gain medium has influence on dissipative soliton characteristics in passively mode-locked Er-doped fiber laser. The research in this paper has important theoretical and practical significance.     

Effects of Yb:Er-codoping on suppressing self-pulsing in Er-doped fiber lasers

The effective pump rate for Er-doped fibers by using Yb codoping is analyzed. We show that the level of the pump power required to suppress the ion-pair induced self-pulsing in Er-doped fiber lasers can be significantly decreased by using Yb:Er-codoped fibers due to the increased effective pump rate. Our results show the potentiality of developing stable single-frequency or high-repetition-rate mode-locked fiber lasers by using high-gain Yb:Er-codoped fibers with laser diodes as pump sources.     

基于内嵌FBG的Sagnac环的双波长光纤激光器

提出了一种内嵌光纤Bragg光栅(FBG)对的Sagnac环结构双波长掺铒光纤(EDF)环形激光器。对内嵌FBG对的Sagnac环的滤波特性进行了理论分析,实验获得了输出波长分别为1 554.92nm和1 555.2nm的稳定双波长光纤激光,边模抑制比约为65dB,功率稳定性优于0.2dB,波长稳定性优于0.02nm。     

环形腔掺铒光纤激光器输出特性理论与实验研究

对由不同长度的掺铒光纤和不同分光比的耦合器构成的光纤环形腔激光器的输出特性进行了理论和实验研究。理论分析表明,激光器的输出功率、斜率效率与掺铒光纤的长度、耦合器的分光比有关,且存在最佳值。最后通过实验得到,在泵浦功率为120 mW,掺铒光纤的掺杂浓度为4 000 ppm下,最佳的掺铒光纤长度为3 m左右,最佳输出耦合比在80%附近,与理论分析基本一致。     

几种新型多波长光纤激光器

综合报道几种新型多波长光纤激光器 ,并对这些激光器的机理、实验装置和研究结果进行了详细介绍 ,对今后多波长激光器的发展方向作一展望。     

多波长掺铒光纤激光放大器的放大特性研究

为了研究多波长掺铒光纤激光放大器的放大特性,在单频放大器的基础上,忽略放大自发辐射,推导了描述多波长掺铒双包层光纤放大器的稳态速率方程组,建立了多波长掺铒光纤放大器的理论模型。利用该模型对单波长放大、双波长放大、四波长放大的特性,进行了数值模拟和理论分析;以四波长的激光信号放大为例,对多波长掺铒光纤放大器的放大特性,均衡增益特性进行了研究。结果表明,在单波长注入情况下,光纤放大器的掺杂光纤存在最佳光纤长度为8m;与小信号放大不同,大功率掺铒光纤放大器在1530nm~1560nm之间增益谱趋于平坦;双波长放大输出功率差随着波长间隔的增加线性增大波长间隔为20nm时,通过调节输入信号功率比可以实现最大功率差6.855W的功率均衡补偿;四波长放大时,通过信号功率配比之后的四波长激光输出功率最大偏差为0.28W,在一定范围内实现了均衡增益。这一结果对于掺铒光纤激光的多波长激光输出以及在激光多普勒测风雷达中的应用具有一定帮助。     

Polarization-maintaining fiber Bragg gratings for wavelengthselection in actively mode-locked Er-doped fiber lasers

Fiber Bragg gratings written in polarization-maintaining fiber are proposed for wavelength selection in actively mode-locked Er-doped fiber lasers. Combined with single-polarization optical circulator, they form unidirectional transmission filters that can be incorporated in polarization-maintaining laser cavities. We have fabricated such a grating in hydrogen-loaded PANDA fiber and we have incorporated it in a polarization-maintaining actively mode-locked Er-doped fiber laser designed to generate soliton-like pulses. Dependencies of pulse duration and spectral width on average intracavity power were measured. The power range over which soliton-like pulses were generated without pedestals was found to be ultimately limited by the grating's bandwidth     

Highly stable low-noise Brillouin fiber laser with ultranarrow spectral linewidth

We demonstrate an all-fiber high-power single-frequency Brillouin fiber ring laser with maximum power of 100 mW at 1.55 /spl mu/m, which is actively stabilized by using the Pound-Drever-Hall frequency-locking scheme. Significant reduction (/spl sim/20dB) of both relative intensity noise and frequency noise was observed in the Brillouin Stokes radiation as compared with those noises of its pump source, a narrow-linewidth Er-doped fiber laser. Ultranarrow spectral linewidth of the Brillouin fiber lasers was investigated by both delayed self-heterodyne technique and heterodyne beat technique between two independent Brillouin fiber lasers.     

双包层掺铒光纤激光器的数值模拟与实验

对双包层掺铒光纤激光器进行理论上的数值模拟和实验研究.根据数值模拟计算,选择2.5m双包层掺铒光纤,利用包层抽运技术,采用大功率半导体激光器作为抽运源,在入纤抽运功率为4.5W时,获得功率670mW的1.56μm激光输出.     

Mode-locking of in-line coupled-cavity fiber lasers usingintra-core Bragg gratings

The report the observation of self-mode-locked laser pulses from in-line coupled-cavity (ILCC) fiber lasers, consisting of an optically pumped Er-doped fiber main cavity and an auxiliary Si fiber cavity formed by using three intra-core Bragg gratings. Mode-locked pulses at a repetition rate of 100 MHz have been obtained with an input pump threshold as low as 10 mW     

Studies on Instantaneous Characteristics of Er-Doped Fiber Laser

In this paper, instantaneous state characteristics of Er-doped fiber lasers (EDFLs) are studied. The fluctuation function of Er-doping ion and photon population density are solved under small pump perturbation. Furthermore, the damp and the resonance properties of the relaxation oscillation and relationships with EDFLs' parameters are discussed in detail.     

光纤激光同带级联抽运的研究进展

光纤同带级联抽运的特点是以高亮度激光作为抽运光,且抽运光与激光的波长比较接近,处于激活离子的同一能带内.它最大的优点是在光纤高功率放大时量子亏损小,可以较好地减小热效应的影响,同时能使用较短的光纤来避免非线性效应的发生.针对同带级联抽运技术在高功率光纤中的重要性,简单综述了国外掺镱、掺铒、掺铥、掺钬光纤同带级联抽运的实...     

温度对L波段EDFA增益斜率影响的实验研究

实用的L波段EDFA(掺铒光纤放大器)常采用多段铒纤和多泵浦的复杂结构。对一种复杂结构的L波段EDFA的温度特性进行了实验研究,发现在不同的输入光功率下,L波段短波侧(约1 570～1 582nm)的增益谱可按相反的方式随温度而变化,并从理论上解释了此现象。实验结果表明,铒纤的温度和增益斜率之间仍然存在很好的线性关系。控制铒纤温度就可以调整L波段EDFA的增益斜率,获得平坦的增益。     

980nm InGaAs应变量子阱激光器及组合件

利用分子束外延技术研制出了高质量InGsAs/GaAs应变量子阱材料及量子阱激光器.脊形波导窄条形量子阱激光器的阈值电流和微分量子效率分别为15mA和0.8 W/A,线性输出功率大于150mW,基横模输出功率可达100mW.InGaAs应变量子阱激光器和单模光纤进行了耦合,其组合件出纤光功率典型值为40mW,最大值可达60mW.显示出了高的基横模输出功率和高的耦合效率.其组合件在40～60mW下,中心发射波长在977nm.满足了对掺铒光纤高效率泵浦的波长要求,成功地研制出适于掺铒光纤放大器用的应变量子阱激光器.     

基于受激布里渊散射的自调Q掺铒光纤激光器简化模型

文中分析了在980nm低功率连续泵浦源泵浦的条件下基于瑞利(RS)受激布里渊散射(SBS)效应的掺铒光纤激光器的自调Q过程。根据泵浦功率与重复频率、有效单模光纤长度与输出功率、有效单模光纤长度与脉冲宽度(FWHM)以及光纤干涉环分光比与输出功率等关系,通过仿真得知单模光纤长度为10m和光纤干涉环分光比为70:30时的输出功率最大,得到了最佳有效单模光纤长度和最佳光纤干涉环分光比,优化了激光器结构参数,并建立了自调Q掺铒光纤激光器的简化模型。     

一种实用化的高功率低噪声波长连续可调光纤激光器

报道了一种基于光纤光栅 (FBG)的高功率可调谐环形腔掺铒光纤激光器。该激光器由 980nm激光二极管(LD)抽运 ,在 15 6 2nm波段获得了线宽小于 0 0 4nm的激光输出 ,调谐范围可达 4 6nm ,输出波长复现性误差小于 0 0 8nm。由于铒光纤选择了最佳长度 ,并在光纤环路中引入两个隔离器抑制噪声 ,提高了信噪比 ,激光器输出的最大功率可达 4 2 8mW ,此时功率稳定性为± 0 0 3dB ,斜率效率为 7 3%。     

0.98- mu m strained quantum well lasers for coupling high optical power into single-mode fiber

An investigation of epitaxial-layer structures has yielded narrow ridge waveguide structure lasers capable of coupling high optical power into single-mode fiber (SMF). An optical power of well over 60 mW in SMF was obtained for a 2- mu m-wide ridge waveguide laser with a guided separate-confinement-heterostructure (SCH) epitaxial structure. Calculated results indicate that the stringent limit imposed on 0.98- mu m wavelength detuning is relaxed for such high optical power coupled into a SMF. The 0.98- mu m strained-quantum-well lasers thus show considerable promise as a practical low-noise pumping source for Er-doped optical-fiber amplifiers.<>     

Polarization characteristics of fiber DFB lasers related to sensingapplications

An experimental and theoretical investigation of how the polarization mode competition and beat frequency of Er-doped fiber distributed-feedback lasers depend on perturbations such as localized transverse forces, back reflections, or changes in pump polarization is reported. Good agreement between the experiments and a comprehensive theoretical model is obtained. Use of a dual-polarization laser as a transverse force sensor with a resolution on the order of 1-100 nN/√Hz above 20 Hz is also discussed