有源光纤环形腔进行频率调谐窄线宽激光的方法

本文提出用有源光纤环形腔来获得精确调谐窄线宽激光的新方法，理论分析结果表明：幅值（或相位）调制产生的频宽扩展对腔带宽的影响很小，滤波输出激光的线宽约等于入射光随机初相位决定的线宽，有源腔对滤波输出激光还有光放大作用。     

高功率线偏振窄线宽光纤激光器TMI抑制

高功率线偏振窄线宽光纤激器在功率光谱合成、相干探测等方面具有广泛的应用前景。在高功率线偏振窄线宽光纤激光器中,模式不稳定(TMI)效应是限制其功率提升的主要因素之一。本文分析了TMI效应对高功率线偏振窄线宽光纤激光器输出功率的影响,提出了TMI效应的抑制方法。文章采用长波泵浦技术,输出功率100mW的单频激光器作为种子源,相位调制器将种子源线宽展宽至25GHz,经三级放大,最终实现了线宽25GHz、功率22 kW、中心波长1064nm、消光比98的线偏振窄线宽激光输出,光束质量M2x=12、M2y=121。分析了泵浦波长对TMI效应的影响:由于光线芯径较小(20μm),增益光纤对泵浦光吸收系数较高(18dB/m@976nm),纤芯温度较高,加上泵浦光量子亏损引入的热,导致纤芯折射率发生变化,较低功率下发生TMI效应,当泵浦波长向长波偏移时,泵浦光的量子亏损降低,同时泵浦吸收系数也降低,无论在光纤全长、还是单位长度上的热分布均减小,增大了TMI阈值,提升了线偏振窄线宽光纤激光器的输出功率。     

窄线宽光纤激光振荡器研究进展（特邀）

窄线宽光纤激光器在遥感探测、非线性频率转换和光束合成等领域具有重要的应用价值。介绍了窄线宽光纤激光振荡器的典型谐振腔结构及其工作原理,从实现更窄线宽的角度梳理了单频选模技术,从获得更高功率的角度梳理了功率提升技术,综述了窄线宽光纤激光振荡器的研究现状,并对窄线宽光纤激光技术的发展进行了展望。     

高功率窄线宽光纤激光的研究进展与发展趋势

高功率窄线宽光纤激光器具有光束质量好、结构紧凑等优点,在相干合成、光谱合成以及非线性频率变换等领域具有广泛的应用前景,基于窄线宽光纤激光相干合成、光谱合成的激光系统性能指标已经超越单束激光的最高性能,基于窄线宽光纤激光非线性频率变换的激光也实现了同类波段激光的最高性能。分析窄线宽光纤激光功率提升同时保持光束质量过程中产生的物理机制和面临的技术挑战,详细介绍学校课题组在高功率窄线宽光纤激光方面取得的代表性成果,特别是高光束质量的7 kW级非线偏振窄线宽激光和5 kW级线偏振窄线宽激光,不仅是同类激光的最高功率值,也逼近了同等条件下非窄线宽光纤激光的功率极限。根据近年来理论研究和技术攻关结果,结合国内外研究现状,对高功率窄线宽光纤激光未来几个发展趋势进行预判。     

6.7 kW全国产化窄线宽三包层光纤激光器

为了实现高功率光纤激光的窄线宽输出,研究了基于大模场三包层掺镱光纤（LMA-YTF）高功率窄线宽光纤激光的热效应和四波混频(FWM)效应。基于FWM效应模型,仿真分析了大模场三包层光纤(LMA-TCF)放大器光谱展宽的影响因素。建立了LMA-YTF的热分布模型,分析了大模场三包层光纤(LMA-YTF)中第二包层功率占比对光纤温度以及泵浦功率上限的影响,讨论了聚合物涂层导热系数和外部温度对光纤温度的影响,实验对比了不同反向合束器的泵浦功率上限,结果表明第二包层功率占比低的(6+1)×1合束器比(9+1)×1合束器拥有更高的泵浦功率上限。基于全国产化器件搭建了一台三包层光纤激光器,实现了输出功率6.7 kW、3 dB线宽为0.32 nm的激光输出。     

275W MOPA结构全光纤窄线宽掺镱光纤激光器

高功率窄线宽激光在相干合成、非线性频率转换、激光雷达、重力波探测等领域有着广泛的应用。光纤激光具有出光阈值低、电光效率高、光束质量好等优点,使其得到飞速发展。基于主振荡功率放大(MOPA)结构的全光纤激光器,无需空间光路调节,不仅兼有一般光纤激光的优点,还有结构     

高功率窄线宽光纤放大器及放大线宽特性

研制了高功率窄线宽光纤放大器.该放大器采用双级放大结构,其中第一级预放为掺Er3+光纤放大器,第二级功率放大采用10 m长的Er3+/Yb3+共掺双包层光纤作为增益介质,抽运源采用两支波长为980 nm的大功率激光二极管.当抽运功率为10.7 W时,得到放大激光输出功率为1.94 W,光一光转换效率为17%,斜率效率20%.采用延迟自外差方法对种子激光器及各级放大器输出的激光线宽进行了测量,测量结果表明窄线宽激光谱线经过掺Er3+光纤与双包层光纤放大后均有不同程度的明显展宽.分析认为激光线宽展宽的主要原因是由于种子激光器中弛豫振荡或自脉冲的强度波动引起的自相位调制.     

保偏光纤饱和吸收体单频窄线宽光纤激光器

研制了一种基于保偏(PM)光纤可饱和吸收体结合光纤光栅Fabry-Perot(FBG F-P)标准具的单频窄线宽光纤激光器.该激光器以高增益掺Er3+光纤(EDF)作为增益介质,采用行波环形腔消除空间烧空效应,并结合FBG F-P标准具选模,实现激光器单频运转.用一段PM EDF作为可饱和吸收体抑制跳模,以获得高效、稳...     

短腔型超窄线宽低噪声光纤激光技术综述

随着激光雷达、引力波探测和光学原子钟等新技术的兴起和研究的不断深入,光学精密测量覆盖的应用领域的广度和深度都在拓展,传统自由运转的激光器其稳定性难以满足高精密测量的应用要求。超窄线宽、超低噪声和长期稳定的光源已成为该领域迫切追求的目标。光纤激光器具备结构紧凑、易于集成化和极限线宽窄等特点,通过噪声抑制和稳频技术输出超稳定、超窄线宽激光,近年来逐渐成为热点研究方向。本文从光纤激光器的噪声理论出发,介绍了光纤激光器的噪声来源、分类及测试方法,基于噪声理论,分类总结了光纤激光器强度噪声和频率噪声不同抑制技术的原理、发展历程及现阶段进展,并对窄线宽光纤激光器的发展趋势做了展望。     

窄线宽光纤激光器关键技术研究

文章介绍了实现窄线宽光纤激光器的线宽压缩方法,并采用掺Er^3＋光纤作为增益介质,980nmLD激光器作为泵浦源,直线腔结构,光纤环行镜和光纤光栅共同作为腔镜,实现中心频率在1550nm波段的单频激光输出,并讨论了其关键技术和影响因素,为同类激光器的研制提供了参考。     

1.63kW单纤单振单模连续全光纤激光器

报道了一种单纤单振单模连续全光纤激光器,工作波长为1 080nm,输出功率可达1.63kW。激光器使用7个输出功率为300 W、工作波长为976nm的半导体激光器(LDs)充当泵浦源,并利用短腔长结构成功地抑制了受激拉曼散射(SRS)。测试结果显示,所获得激光的光谱信噪比(SNR)大于40dB,1h内的功率不稳定度小于1%,光-光转换效率约为75.46%。此外,通过对光纤盘绕的合理设计,有效地抑制了光纤中的高阶模式,在满功率输出时成功地获得了单模激光(M2<1.1)。     

A widely tunable narrow-linewidth triple-wavelength erbium-doped fiber ring laser

A widely tunable narrow-linewidth simultaneous triple-wavelength oscillation erbium-doped fiber ring laser (EDFRL) is investigated in detail. The EDFRL can produce double-wavelength oscillations with the same polarization output, as well as another widely tunable wavelength oscillation with orthogonal polarization in both the C-band and the L-band. By preventing two polarization-mode competitions, we have achieved a stable single-longitudinal-mode triple-wavelength lasing output along with a minimum side-mode suppression ratio of 40 dB.     

Stable single-mode compound-ring erbium-doped fiber laser

In this paper we report the fabrication of a robust, tunable single-longitudinal-mode compound-ring Er³⁺-doped fiber laser. The laser is fundamentally structured on an all-fiber compound-ring resonator in which a dual-coupler fiber ring is inserted into the main cavity. When combined in tandem with a mode-restricting intracavity tunable bandpass filter, the compound-ring resonator ensures single-longitudinal-mode laser oscillation. The laser can provide up to 20 mW output power over much of its 1525 to 1570 nm wavelength tuning range. The short-term linewidth of the laser output measured is less than 5 kHz. The laser frequency is actively stabilized for a long time by exploiting the inherent filter nature of the compound-ring resonator. The reduction of an associated frequency modulation is also discussed in detail     

Bidirectional single-mode Er-doped fiber ring laser

Rare Er-doped fiber lasers have been studied for fibe sensor applications with the advantage of frequency readou [1,2]. Due to this advantage, gyroscope application for a bidi rectional Er-doped fiber-ring laser was also demonstrated They also have high s…     

A 43-W C-band tunable narrow-linewidth erbium-ytterbium codoped large-core fiber laser

The authors report a widely tunable and highly efficient cladding-pumped erbium-ytterbium codoped large-core fiber laser, generating up to 43 W of output power at /spl sim/1.5 /spl mu/m with a narrow linewidth (0.16-nm full-width at half-maximum) and a good beam quality (M/sup 2/<1.7). By use of a tunable narrow-band fiber Bragg grating, the laser wavelength was tuned from 1532 to 1567 nm, limited upwards by the tuning range of the fiber grating. The overall slope efficiency was 32% with respect to launched pump power.     

用腐蚀熔融法制造单模激光二极管与单模光纤相耦合的半球微透镜

近年来由于单模光纤研究的极大成功，促进了单模光纤通信系统和单模光纤应用技术的迅速发展。单模光纤的实际损耗已降到接近理论值，因此为进一步改善单模光纤传输系统的信噪比，提高激     

Low-noise narrow-linewidth fiber laser at 1550 nm (June 2003)

We present a compact integrated fiber laser with more than 200 mW of output power. It combines polarized fiber output with very narrow linewidth of less than 2 kHz. The coherence length of the laser is measured to be longer than 5 km. The laser features high mode stability of less than /spl plusmn/10 MHz over hours. The relative intensity noise (RIN) spectrum is dominated by a peak at the relaxation oscillation frequency and is shot-noise limited otherwise. The RIN peak at 1 MHz is reduced to /spl sim/-130 dB/Hz by integrating a negative feedback circuit. In addition to thermal wavelength tuning, the laser frequency can be modulated at a bandwidth of up to 10 kHz via the piezoelectric effect.     

A broad-band superfluorescent fiber laser using single-mode dopedsilica fiber combinations

We demonstrate the possibility of broadening the emissions spectra of superfluorescent fiber lasers by combinations of different kinds of single-mode doped silica fibers. We obtained an optical bandwidth of more than 70 nm (FWHM) between 1030 and 1100 nm using Nd:Cs, Nd:Ge, and Yb-doped fibers. The total output power measured from the single-mode fibers was more than 100 μW in a single pass configuration     

100mW窄线宽低噪声光纤激光器的实验研究

利用国产高掺镱光纤和光纤布拉格光栅(FBG)对,通过分布布拉格反射式(DBR)谐振腔结构设计,实验研究了高功率、窄线宽、低噪声的光纤激光器;并对其输出激光特性进行了研究.同时,制作完成了一台全光纤结构的光纤激光器样机.