Nd：YLF激光器中以负反馈强迫的自锁模技术

本文乎次利用ＧａＡｓ光电导开关，控制Ｎｄ：ＹＬＦ激光器腔内的Ｑ值，实现自锁模。稳态自锁脉冲序列长５０μｓ，单脉冲脉宽为１０ｐｓ，能量为０．１μＪ。     

用单晶硅在Nd：YAG激光器中实现被动锁模

在Ｎｄ：ＹＡＧ激光器中，用单晶硅实现了被动锁模，得到了脉冲定义为２８ｐｓ左右，能量为约３μＪ的锁模脉冲，并对锁模机理作了初步解释。     

半导体激光泵浦锁模调QNd：YAG板条激光器

报道准连续６０Ｗ半导体激光二极管侧面泵浦的锁模调ＱＮｄ：ＹＡＧ板条激光器，调Ｑ锁模的激光脉冲宽度（ＦＷＨＭ）为６０ｐｓ，调Ｑ脉冲包络宽度为２５０ｎｓ，积分能量１６３μＪ，最大锁模脉冲的峰值功率超过１００ｋＷ。     

半导体激光泵浦预激光锁模调Q固体激光器研究

报道半导体激光侧面泵浦预激光锁模调Ｑ的Ｎｄ：ＹＡＧ固体板条激光器，预激光锁模调Ｑ的激光脉冲宽度为３６ｐｓ，调Ｑ包纤各心的锁模单脉冲能量超过７μＪ，相应的峰值功率达２００ｋＷ。     

利用KTP晶体实现1.08μmNd：YAP激光器锁模

本文描述了利用ＫＴＰ晶体和腔的基波输出镜构成非线性镜实现１．０８μｍＮｄ：ＹＡＰ激光器的被动锁模。实验表明，这种新的锁模技术比用染料作可饱和吸收体的被动锁模技术有很多突出的优点，具有很大的发展潜力。实验测得锁模时基波１．０８μｍ输出２．４ｍＪ，二次谐波０．５４μｍ输出０．５ｍＪ（同样条件下的静态输出为２．５ｍＪ），基波脉冲的平均脉宽为４０ｐｓ。     

稳态锁模产生4ps激光脉冲

首次利用ＧａＡｓ光电导开关，控制Ｎｄ：ＹＬＦ激光器腔内Ｑ值，实现稳态锁模，获得脉宽和能量稳定性极高的４ｐｓ激光脉冲。     

TW级Ti：Al2O3飞秒激光放大器

报道ＴＷ（１０＾１２Ｗ）级Ｔｉ：Ａｌ２Ｏ３飞秒激光放大器的研究，采用Ｔｉ：Ａｌ２Ｏ３自锁模激光振荡器和脉冲啁啾放大技术，获得了能量为８４ｍＪ，脉宽为７５ｆｓ的放大光脉冲，峰值功率达到ＴＷ量级。     

Cr^4＋：YAG在对撞脉冲锁模的Nd：YAG激光器中实现被动锁模的研究

在理论上提出了Ｃｒ＾４＋：ＹＡＧ作为可饱和吸收体在Ｎｄ：ＹＡＧ激光器中实现被动锁模的可能性，运用速率方程组导出在强激光脉冲作用下Ｃｒ＾４＋：ＹＡＧ激发态吸收的恢复时间和饱和光强。实验上在带有抗共振环结构的接近于介稳腔的脉冲式Ｎｄ：ＹＡＧ激光器中用Ｃｒ＾４＋：ＹＡＧ作为可饱和吸收体实现被动锁模运转，得到能量１３．５ｍＪ、平均脉宽１８０ｐｓ的锁模脉冲序列。     

56 MHz重复频率端泵SESAM连续波锁模Nd∶YVO4激光器

为了增大皮秒注入种子激光的能量,获得较高的激光放大效率和信噪比,关键是要在保持较高的平均锁模激光功率下实现连续波锁模激光器的低重复频率运转。通过选取五镜折叠激光谐振腔腔型和参数设计,克服了随着腔长增加损耗加大而导致的激光锁模不稳定的困难。分析了较长腔长条件下工作物质和SESAM光斑尺寸的大小和变化,及其对激光器稳定性的影响。由于SESAM饱和工作和稳态条件的能量要求,在激光谐振腔调整过程中,对应臂长的光程互补变化。实验中采取腔长和晶体热控制方式,优化了激光谐振腔的工作参数,实现了脉冲能量10.7 nJ,重复频率56 MHz,平均功率1.2 W的SESAM连续波锁模激光输出。     

参量自注入放大产生皮秒中红外脉冲

首次采用参量自注入放大方法产生了皮秒中红外超短脉冲．该方法的优点是仅使用１块红外非线性晶体，实验装置简单，成本低．入射光源是锁模皮秒Ｎｄ：ＹＡＧ激光器，用来泵浦ＡｇＧａＳ２单晶，经过参量过程辐射３—１０μｍ的皮秒脉冲激光．最大红外脉冲激光输出能量为１４μＪ．     

Colliding pulse mode-locked Nd: YLF laser with negative feedback control by GaAs Photoconductive switch

A picosecond colliding pulse mode-locked Nd: YLF laser with negative feedback provided by GaAs photoconductive switch was described. Optical pulse with～4ps duration, 10μJ energy and about 7μs long pulse train were generated.     

Pulse energy modulation of the cw-mode-locked 1.32 μm Nd-YAG-laser by drive frequency detuning

The frequency of an acousto-optic mode-locker is detuned from the fundamental resonance frequency of the cavity resulting in undamped oscillations of the laser pulse energy. The envelope of the mode-locked pulse train consists of spikes 10 μs wide with a repetition time of 46 μs. The energy of the mode-locked pulses in a spike is increased by up to a factor of 50 compared to a cw-mode-locked pulse. The pulse width can be as short as 700 ps.     

Diode-laser pumped high-power and actively mode-locked Nd:YLF laser with fast switching

In an actively mode-locked laser, self-phase modulation can make pulse shorter at the expanse of causing instability at high pumping power. Using fast switching on the acousto-optic modulator, we can generate an actively mode-locked pulse train with shorter pulse width and higher average power than that driven by a sinusoidal signal. A 9-ps pulse train was generated in a mode-locked laser with an average power of 600 mW whose power level, to our knowledge, is the highest for diode-pumped and mode-locked Nd:YLF lasers.     

Generation of a single tunable ultrashort light pulse

A novel system for generating single tunable ultrashort light pulses of high power is described. The pulse train from a mode-locked flashlamp pumped dye laser passes through an amplifier, which is pumped by an N₂ laser. As gain is only available for a few nsec, only one pulse in the train gets amplified. The energy of the resulting single pulse is about 100 μJ.     

Pulse picking by phase-coherent additive pulse generation in an external cavity

We have implemented a simple method for generating an "amplified" phase-coherent light pulse in which a pulse train of phase-coherent, equidistant input light pulses from a mode-locked Ti:sapphire laser is coupled into a ring cavity resonator whose length is matched to the mode-locked pulse repetition frequency at 82 MHz. Pulses are thus coherently superimposed and added inside the buildup cavity and form an intense pulse that is switched out from the cavity via a fast acousto-optic modulator. The method thus provides a pulse train at a reduced and controlled repetition frequency and with higher pulse energies than the original mode-locked pulses.     

对撞锁模染料激光器中锁模脉冲列的耦合效应

论述了在对撞锁模染料激光器中必然存在锁模脉冲列耦合效应,此效应使输出脉冲较宽,且脉宽不稳定。用适当加厚锁模染料层等办法减弱该效应会使脉冲变窄且脉宽稳定。     

High-repetition-rate coherent femtosecond pulse amplification with an external passive optical cavity

We demonstrate a general technique for enhancement of femtosecond pulses from a pulse train through their coherent buildup inside a high-finesse cavity. Periodic extraction of the intracavity pulse by means of a fast switch provides a net energy gain of 42 to >70 times for 38-58-fs pulse durations. Starting with an actively stabilized but otherwise standard mode-locked laser system, we demonstrate pulses of >200-nJ energy.     

Measurement of pulse width and amplitude jitter noises of gigahertz optical pulse trains by time-domain demodulation

We propose a technique for measuring both pulse width and amplitude jitter noises of high-repetition-rate optical pulse trains and the cross correlation between these noises as well. The technique is based on time-domain amplitude demodulation of three harmonic components of the detected pulse train. We applied this technique to characterize noises of a gigahertz optical pulse train generated by an actively mode-locked Er-doped fiber laser. Correlation between pulse width jitter and pulse amplitude jitter was observed at low frequencies in this laser. Unlike relaxation oscillation noise, low-frequency noise is free from pulse energy jitter. Owing to its ability to measure pulse width jitter in addition to amplitude and phase jitters, this technique is of great interest for characterizing noises of a wide variety of optical pulse train sources.     

全光纤主动锁模2 μm掺铥脉冲激光器

报道了全光纤结构主动锁模掺铥脉冲激光器,中心波长为1950 nm。利用电光相位调制器对光纤激光器进行腔内相位调制,获得了重复频率为11.884 MHz的主动锁模脉冲输出,脉宽为816 ps。改变泵浦功率、调制信号的频率和幅度,获得了重复频率为4~18 kHz的弛豫振荡调制稳定脉冲输出。锁模和弛豫振荡调制获得的输出脉冲能量波动低于7%。     

Ti:sapphire laser pumped by a long train of pulses from mode-locked Nd:YAG laser with negative feedback

Investigation of the buildup dynamics of a Ti:sapphire laser pumped by a 500 ns long second harmonic pulse train from a mode-locked Nd:YAG laser with a passive negative feedback using GaAs is reported. The 400 ns long output pulse has a buildup time of 70 ns for a pump energy of 1.25 mJ. A slope efficiency of 15.1% was achieved with a 94% reflective output coupler.