调Q主动锁模Nd:YAG皮秒激光器实验

为了提高锁模脉冲输出质量,利用"调Q+主动锁模"的方式对Nd:YAG固体激光器进行了实验研究。采用Cr4+:YAG晶体、声光调制器作为调Q和主动锁模的元件。为了减小腔内的FP标准效应,镜Nd:YAG棒的端面切割成布儒斯特角。在实验中比较和分析了主动锁模、调Q主动锁模两种情况下Nd∶YAG激光器的输出特性。其中,主动锁模脉冲序列的单脉冲宽度为173 ps,调Q主动锁模的脉冲系列单脉冲宽度为169 ps,两种方式输出波形的锁模深度和锁模几率均在95%以上。对调Q主动锁模脉冲的输出能量进行了测量,结果表明其有较大提高。     

Frequency tuning and pulse generation in a fiber laser with anintracavity semiconductor active filter

The authors demonstrate optical frequency tuning by direct electrical means as well as FM and AM mode-locking in an erbium-doped fiber laser with an intracavity distributed Bragg reflector active filter/modulator. They obtained a 6 nm discrete tuning range and pulses of 38 and 78 ps duration in AM and FM mode-locking, respectively     

TEACO_2激光器主动锁模的实验研究

利用一米长光预电离 TEA CO_2激光器,腔内置一布氏角声光调制器做损耗元件,进行锁模实验研究。叙述了设计考虑、实验装置及测试结果。     

Characterization of a photonic active integrated antenna using a direct off-air transmission technique

This article presents a characterization study of a state-of-the-art 40 GHz mode-locked laser using a hybrid integrated microstrip patch antenna and bias-T circuit. A passive mode-locking range of 300 MHz is measured using this technique by tuning the gain and saturable absorber bias values for a maximum wireless distance of 15 cm. The passive mode-locking signal is detected by a direct off-air method from a photonic active integrated antenna. This signal can be used as a remote local oscillator to downconvert incoming signals as part of a bidirectional system for in-building/campus wide remote antenna units in next generation millimetre-wave radio-over-fibre systems.     

5.5-mm long InGaAsP monolithic extended-cavity laser with anintegrated Bragg-reflector for active mode-locking

A 5.5-mm-long monolithic extended-cavity laser with an integrated Bragg-reflector in the InGaAsP system for active mode-locking at low repetition rates at a wavelength of 1.55 μm has been fabricated. The device, which is designed to be used as a pulse source in long-distance soliton systems and optical time-division multiplexed systems, generates 20-ps-wide transform-limited pulses with a time-bandwidth product of 0.34 at a repetition rate of 8.1 GHz     

Frequency and timing stability of mode-locked semiconductorlasers-passive and active mode locking up to millimeter wave frequencies

A theoretical understanding of the fundamental frequency and timing jitter of active and passive mode-locked semiconductor lasers is developed. These results are compared with experimental observations for a wide range of mode-locking frequencies, and are found to predict the correct trends as well as having good quantitative agreement. The theory is based only on excitation of mode-locked supermodes by spontaneous emission, and these results can therefore be regarded as fundamental. The nature of these fluctuations is such that, for active mode locking, an external reference signal locks the absolute frequency of the mode-locked output, while spontaneous emission causes the phase of the mode-locked signal to fluctuate within finite bounds, which results in a timing jitter of the mode-locked pulses     

Bandwidth-limited picosecond pulse generation by hybrid mode-locking in a ring cavity GaAlAs laser

Bandwidth-limited picosecond pulses have been obtained using hybrid active/passive mode-locking in an external cavity semiconductor diode ring laser. Active mode-locking by application of sinusoidal RF modulation at the cavity round-trip frequency to a diode laser providing gain is supplemented by passive mode-locking in a second laser which is biased to provide saturable loss. Simultaneous streak camera and scanning Fabry-Perot interferometer measurements show that bandwidth-limited pulses of 25 Ps duration are obtained. Operation is not limited to near laser threshold, and frequency detuning sensitivity is improved when compared to the case of purely active mode-locking.     

主被动锁模Nd∶YLF激光器

在脉冲抽运主动锁模Nd∶YLF激光器中 ,用倍频晶体CLBO和双色镜构成的非线性镜取代输出镜 ,实现了主被动锁模 ,与纯主动锁模相比 ,脉冲宽度压缩了 8倍 ,获得了 15ps的锁模脉冲     

Actively initiated quasi-passive mode-locking in a CW SELFOC Nd:glass laser

Actively initiated quasi-passive mode-locking has been achieved in a small-power CW SELFOC Nd:glass laser. Three means have been taken to enhance the pulse intensity incident on a saturable dye to a magnitude sufficient for nonlinear absorption initiation: 1) tight focusing, 2) controlled spiking oscillation, and 3) auxiliary active mode-locking. Mode-locked pulses having an 11-12-ps pulsewidth were obtained. Interpretation concerning the observed mode-locked-pulse intensity-correlation curves is presented. To obtain satellite-pulse-free mode-locked pulses, a modified mode-locking process with sufficiently long buildup time is considered.     

光纤激光器技术

在概述光纤激光器基本原理、主要特性及其多种分类方法的基础上,首先介绍了双包层光纤激光器的工作原理和最新进展。通过对几种典型实验装置的分析阐述了光纤激光器的多波长产生机制。并详细讨论了光纤激光器产生锁模脉冲的三种技术：采用振幅或相位调制器的主动锁模技术、利用非线性效应的被动锁模技术以及混合锁模技术,最后比较了这三种技术和实验装置的优缺点并介绍了它们的最新发展情况。     

Passive Q-Switching and Mode-Locking of Erbium-Doped Fluoride Fiber Lasers at 2.7 μm

Passive Q-switched and mode-locked operation of a 2.7-μm fluorozirconate fiber laser is reported. Both mode-locking and Q-switching were attained by means of InAs epilayers used as saturable absorbers. Another technique used was the so-called flying-mirror mode-locking, whereby an external resonator with a vibrating mirror is coupled to the active fiber resonator. Both techniques yielded Q-switched pulses containing trains of mode-locked pulses with durations shorter than 2.5 ns—the resolution limit of the detection unit.     

Tm3+/ Ho3+离子掺杂中红外超快激光技术研究进展（特邀）

稀土离子Tm3+/ Ho3+ 掺杂中红外2 μm波段超快激光由于广泛的应用前景成为近十余年来激光领域的研究热点之一。文中首先综述了稀土离子Tm3+/Ho3+掺杂固体/光纤2 μm波段超快激光锁模技术进展,包括主动锁模技术以及饱和吸收、克尔透镜、非线性偏振旋转、非线性光环形镜、非线性多模干涉等被动锁模技术;其次,结合激光增益介质及色散管理技术回顾了Tm3+/ Ho3+掺杂固体和光纤锁模激光脉冲宽度压缩进展;再次,总结了Tm3+/ Ho3+大能量/高功率超快激光技术及进展;最后,对2 μm波段超快激光发展趋势进行了总结和展望。     

主被动锁模脉冲氙灯抽运Nd:YAG激光器的研究

为了克服主动锁模脉冲能量低、被动调Q锁模稳定性差、锁模不完全的缺点,采用Cr<'4+>:YAG和声光锁模器进行主被动联合锁模脉冲氙灯抽运的Nd:YAG激光器,实验验证和分析了Cr<4+>:YAG被动锁模,声光锁模器主动锁模及两者联合主被动锁模3种情况下输出脉冲的特性.结果表明,主被动联合锁模可得到200mJ输出能量、输...     

20 GHz active mode-locking of a 1.55 ?m InGaAsP laser

Active mode-locking of a 1.55 ?m wavelength InGaAsP laser at repetition rates up to 20 GHz is reported. The pulsewidth is 5 ps at 20 GHz, with a peak pulse power of 18 mW coupled into a single-mode output fibre.     

7 Gbit/s coherent pulse generation in an actively mode-locked GaAlAs diode laser

High-rate coherent pulse generation was demonstrated with a GaAlAs laser system by active mode-locking. Almost transform-limited pulses of about 30 ps duration are obtained at a rate of about 7 GHz.     

Theory for passive mode-locking in semiconductor laser structuresincluding the effects of self-phase modulation, dispersion, and pulsecollisions

We present a theory for passive mode-locking in semiconductor laser structures using a semiconductor laser amplifier and absorber. The mode-locking system is described in terms of the different elements in the semiconductor laser structure. We derive mode-locking conditions and show how other mode-locking parameters, like pulse width and pulse energy, are determined by the mode-locking system. System parameters, like bandwidth, dispersion, and self-phase modulation are shown to play an important role in mode-locking conditions and results. We also discuss the effects of pulse collisions and positions of the mode-locking elements inside the cavity on mode-locking stability and show that these effects can be easily included in the presented model. Finally, we give a number of design rules and recommendations for fabricating passively mode-locked lasers     

透射式SESAM实现掺Yb3+光纤激光器被动调Q锁模

锁模光纤激光器具有体积小、性能稳定及模式好等优点，日益受到关注。利用一种新型的透过式半导体可饱和吸收镜，实现双包层掺Yb^3＋光纤激光器调Q锁模脉冲激光输出。得到的脉冲调Q包络半高宽约500ns，重复频率110kHz，平均输出功率45mW，锁模脉冲重复频率26．7MHz。锁模光路比反射式吸收镜更简单，易于调节，为进一步引入色散补偿元件进行飞秒脉冲的实验研究奠定了基础。     

Active mode-locking of 1.3 μm extended-cavity silicon chip Braggreflector laser

The authors report active mode-locking of an extended-cavity silicon chip Bragg reflector laser. Pulses of 27 ps duration at repetition rates up to 7 GHz, have been achieved with a controllable narrow optical spectrum     

完全锁模半导体激光器

本文对含F-P标准具的外腔半导体激光器进行了主动锁模研究。适当选择F-P标准具参数可形成单一的纵模群振荡,并可因此得到完全锁模光脉冲。实验中得到了脉宽为13.5ps、重复频率为925MHz的光脉冲输出。     

采用一种新型声光调制器锁模的氩离子激光器

主动锁模Ar~+激光器,由于其输出可见光脉冲系列的脉宽、重复周期和脉冲功率的高度稳定性,在高速摄影和同步泵浦染料激光器等超短脉冲技术中受到重视.近年来,激光器的主动锁模多采用声光调制的方法,其优点是效率较高,工作稳定可靠.