用倍频晶体KTP实现Nd：YAG激光锁模的研究

报道用倍频晶体KTP实现Nd:YAG激光锁模的系统研究,给出了该锁模激光器输出脉宽的表达式,并和实验测量值相比较,计算值跟实验结果符合较好.文中还分析了各种参数对该锁模激光输出性能的影响.     

基于新型非线性耦合腔锁模过程的时域理论分析

系统地研究了用带有非线性倍频晶体的附加耦合腔来压窄激光光脉冲的动力学作用过程，报道了该锁模激光系统在瞬态平衡时输出脉冲宽度的具体表达式；另外，通过数值分析计算，给出了该系统锁模激光输出特性优于单腔情形的原因。 关键词：     

基于氧化石墨烯的锁模激光实验

设计了低成本全固态锁模超快激光实验系统,使用透射式氧化石墨烯饱和吸收体作为被动锁模元件,直接插入到腔内,可依次观察到激光的不同运转状态.实验采用结构紧凑的谐振腔设计,获得了二极管端面泵浦Nd∶YVO4晶体的1 064nm连续波被动锁模激光输出,重复频率为81MHz,最大平均输出功率为1.23W,相应的锁模单脉冲能量为15.2nJ.     

自锁模激光器

概述了自锁模激光器的新成就（包括我们自已的工作）。在实验上，自锁模钛宝石激光器可以输出１３ｆｓ的短激光脉冲，这是直接从激光器中获得的最短脉冲；自锁模溴化亚铜激光器可以输出高稳定性的激光脉冲，从而彻底否定了自锁模没有实用价值的传统认识。在理论上，自克尔镜模型解释了自聚焦激光介质引起的锁模现象；增益凹陷模型解释了宽带激光介质自吸收起的锁模现象和窄带激光介质增益谱线分裂引起的锁模现象。最后，对它们的输出     

全保偏被动同步的双色锁模光纤激光器的实验研究

设计并搭建了被动全光同步的全保偏光纤激光系统,该系统能够长时稳定输出时域精确同步的双色超快脉冲。被动同步系统包含两台基于非线性放大环形镜锁模的掺铒与掺镱全保偏光纤激光振荡器,采用主从注入式整体结构,借助注入脉冲在从激光谐振腔中引入的非对易非线性相移,获得了自适应同步的锁模脉冲输出。通过优化主激光注入脉冲能量和从激光器腔内滤波带宽等实验参数,获得了长达26 mm的腔长失配容忍度。该脉冲同步系统具有结构简单、即插即用、稳定性好、保偏输出等优点。     

关于氦氖激光器声光调制锁模的实验研究

本实验中,将声光调制锁模器放置在氦氖激光器中的谐振腔里,控制谐振腔中的增益,使声波的频率调制与激光器固有频率间隔一致,从而达既可以到锁模的效果,又可以增加增益,减少能量损耗。通过功率计与示波器检测出激光脉宽、脉冲周、纵模间隔等物理量,与理论值进行比较,判断激光锁模实验的效果。本实验使用的氦氖激光器腔长大于1.55m,是双面全反射腔,可以利用激光锁模技术得到纵模进行比较,从而获得单色性好的超短脉冲激光。     

采用飞秒光纤激光同步泵浦的自启动锁模钛宝石激光研究

针对常规连续激光泵浦钛宝石激光振荡器不能自启动锁模的缺点,采用倍频飞秒光纤激光同步泵浦,通过调节振荡器腔长与泵浦腔长匹配,实现了飞秒钛宝石激光的自启动锁模。实验中采用3.4 W的倍频掺镱光纤激光同步泵浦钛宝石激光振荡器,获得了平均功率大于130 mW、重复频率75 MHz、光谱宽度大于47 nm、脉冲宽度17 fs的锁模脉冲输出,不仅能够稳定可靠地实现自启动锁模,解决了常规钛宝石激光振荡器锁模启动的困难,而且还具有同步输出1040,800,520 nm三束飞秒激光的特点,为进一步开展飞秒激光相干合成以及光参量放大等研究提供了优势基础。     

低抽运三镜腔自锁模掺钛蓝宝石激光器的理论与实验研究

实现了低抽运三镜腔自锁模掺钛蓝宝石激光器的自锁模运转,对该激光器的自锁模区进行了实验研究,并对象散、稳定性、光束参量和克尔自聚焦强度与腔参量的关系进行了系统的理论计算.该计算为自锁模固体激光器的设计和调整提供了理论依据.     

自锁模掺钛宝石激光器的泵浦研究

对自锁模掺钛宝石激光器的原理作了较详细的描述，指出克尔透镜效应是形成自锁模的主要原因，但是，只有将克尔透镜自聚焦、振荡光参数和泵浦光参数三者结合起来考虑，才能全面了解自锁模的形成过程，本文从速率方程出发，得出了激光介质增益与光束参数的相对变化曲线，并据此来优化自锁模钛宝石激光器的设计，最后，将计算结果与实验作了比较，两者符合得较好。     

C轴YLF激光发射光谱和锁模性质

本文研究了C轴YLF晶体的光谱性质,并利用这种新型激光晶体,进行了主动锁模,被动锁模和主被动锁模实验.C轴YLF激光器直接发射1.053μm激光,锁模脉冲序列能量起伏小于±4%,脉宽起伏不大于±10%.     

Picosecond fluorescence studies by intracavity gain spectroscopy in a modelocked dye laser

This article presents measurements which combine modelocking technique with intracavity spectroscopy. To test this approach, a sample (10^–5 m ethanolic solution of 1,4-dihydroxyanthranquinone) was inserted in a modelocked Ar⁺ ion laser and probed by intracavity pulses of a synchronously pumped dye laser. The probing of the sample results in an amplification of the dye laser output. Maximum output was measured if the pulses of the dye laser temporally overlapped with those of the Ar⁺ ion laser inside the sample. Under this condition, the spectral laser intensity was shaped by the spectrum of stimulated fluorescence which originated from a molecular vibronic state populated by pump laser excitation.Presented at LASERION '91, June 12–14, 1991, München (Germany)     

光折变晶体中二波耦合光强依赖皮秒光脉冲整形

波长为532nm、主脉冲脉宽为55ps、重复频率为82MHz的激光脉冲列在掺Ce的KNSBN晶体中进行二波耦合.当探测脉冲(倒空脉冲)相对于泵浦脉冲有一定时间延迟时,泵浦脉冲发生整形.整形效果随入射总光强的增大而变得越来越明显.实验结果与理论符合很好.     

Coupled cavity modelocking of a Nd:YAG laser using second-harmonic generation

The modelocking of a Nd:YAG laser using second-harmonic generation in an external cavity as the only pulse shortening process is reported. The output of a long pulse Nd:YAG laser was simultaneously modelocked and Q-switched. The average pulse duration was 30–50 ps and the peak power was in the range 60–160 kW.     

Wavelength and duration tunable soliton generation from a regeneratively mode-locked fiber laser

A 10-GHz soliton source with pulse duration between 4-8 ps and wavelength continuously tunable from 1530 to 1563 nm is presented. Using regeneratively mode-locking technology, the harmonically modelocked fiber ring laser could work without pulse dropout at room temperature when no cavity length or polarization maintaining mechanism is available. Applying only one 980-nm laser diode pump, the average output power reaches more than 4 mW.     

Sub-6-fs pulses from a SESAM-assisted Kerr-lens modelocked Ti:sapphire laser: at the frontiers of ultrashort pulse generation

Well-characterized pulses in the two-optical-cycle regime are demonstrated using a Kerr-lens modelocked (KLM) Ti:sapphire laser and phase-sensitive diagnostics. The oscillator employs double-chirped mirrors (DCMs) for dispersion compensation, spectral shaping via wavelength-dependent output coupling, and a semiconductor saturable absorber mirror (SESAM) for reliable operation at up to 300 mW output power and with a repetition rate of ~90 MHz.In the discussion of the experimental results we emphasize how spectral shaping can be used most efficiently in the generation of the shortest possible pulse supported by the Ti:sapphire gain bandwidth.     

Modelocked quantum dot vertical external cavity surface emitting laser

We report the first successful modelocking of a vertical external cavity surface emitting laser (VECSEL) with a quantum dot (QD) gain region. The VECSEL has a total of 35 QD-layers with an emission wavelength of about 1060 nm. In SESAM modelocked operation, we obtain an average output power of 27.4 mW with 18-ps pulses at a repetition rate of 2.57 GHz. This QD-VECSEL is used as-grown on a 450 μm thick substrate, which limits the average output power.     

Picosecond Self-modelocked Wavelength Tunable Ti:Al_2O_3 Laser

1.IntroductionTi:Alzoscrystalasabroadtunablesolid--statelasermaterialbasedonvibronicallybroadenedtransitionsinmetalions,hasseenaresurgenceofresearchanddevelopmentrecently.TheadvantagesofTi:A12O3crystalincludebroadabsorptionandemissionspectrumbandwidth,highbeamqualityandcapabilityofallsolid--stateoperation.KerrlensmodelockedTi:sapphirelaserspumpedbyCWargon--ionlasersarewidelyusedasasourceoffemtosecondopticalpulsesll~'j.KerrlensmodelockingutlizestheorstiealKerreffecttoproduceafastpulse--shor…     

Passively modelocked surface-emitting semiconductor lasers

This paper will review and discuss pico- and femtosecond pulse generation from passively modelocked vertical–external-cavity surface-emitting semiconductor lasers (VECSELs). We shall discuss the physical principles of ultrashort pulse generation in these lasers, considering in turn the role played by the semiconductor quantum well gain structure, and the saturable absorber. The paper will analyze the fundamental performance limits of these devices, and review the results that have been demonstrated to date. Different types of semiconductor saturable absorber mirror (SESAM) design, and their characteristic dynamics, are described in detail; exploring the ultimate goal of moving to a wafer integration approach, in which the SESAM is integrated into the VECSEL structure with tremendous gain in capability. In particular, the contrast between VECSELs and diode-pumped solid-state lasers and edge-emitting diode lasers will be discussed. Optically pumped VECSELs have led to an improvement by more than two orders of magnitude to date in the average output power achievable from a passively modelocked ultrafast semiconductor laser.     

宽可调谐自起振被动锁模掺铒光纤激光器

分析了利用非线性偏振旋转效应作为等效可饱和吸收体锁模的原理,并用该方法构建起环形腔被动锁模掺铒光纤激光器,结合可调谐滤波器腔外滤波的方法实现锁模脉冲波长的连续可调谐.实验中得到自起振、平均输出功率0.313 mW,脉冲半极大全宽度(FWHM)1.5 ps,中心波长1562.3nm,重复频率13.9MHz的稳定被动锁模脉冲序列输出,滤波后输出脉冲中心波长在1553.2～1571.4 nm内连续可调,得到谱宽2.5 nm以下,脉宽小于1.8 ps的限变脉冲输出.