基于大基模体积的10mJ飞秒钛宝石激光再生放大器

文章报导了基于大基模体积的高能量飞秒钛宝石激光再生放大器的设计与实验研究,在重复频率10 Hz、抽运能量60 mJ的激励下,得到了单脉冲能量17.4 mJ的种子脉冲放大结果,压缩后的脉冲宽度为40.6 fs,能量为13.9 mJ.借助于此大基模体积再生腔,仅增加一级多通放大,实现了峰值功率达1.9 TW飞秒激光脉冲输出.结果表明,大模体积再生放大不仅降低了后续放大对抽运能量的要求,也可以单独压缩实现再生腔直接输出10 mJ量级的飞秒激光脉冲,是大能量高峰值功率飞秒激光系统的优质前端.     

采用环形再生腔结构的飞秒激光啁啾脉冲放大研究

采用环形再生腔结构的啁啾脉冲放大技术方案, 在重复频率100 Hz,单脉冲能量33.1 mJ的532 nm激光抽运下, 从钛宝石激光中获得了单脉冲能量9.84 mJ的放大输出, 对应的斜效率达33.1%.在重复频率10 Hz的情况下, 同样获得了单脉冲能量为9.64 mJ, 对应斜效率达36.8%的高效率放大结果. 通过色散补偿压缩该啁啾激光脉冲后的单脉冲能量为6.36 mJ, 脉冲宽度为59.7 fs. 测量结果表明典型的能量不稳定度为1.85%. 关键词： 啁啾脉冲放大 再生放大 飞秒激光 环形腔     

钛宝石激光再生放大器的研究

最近,我们采用上海光机所生产的(5.2×5.5×10)mm 的钛宝石激光晶体作为再生放大器的激光介质,实现了钛宝石激光再生放大器的运转.获得了1.2mJ 的能量输出.再生放大器的泵浦源是调 Q 的倍频 Nd:YAG 激光器,它的输出光脉冲宽度小于10ns,脉冲重复频率为10Hz,实验中为避免损伤晶体,采用的泵浦能量为50mJ.种子脉冲来自于自锁模钛宝石激光器,种子脉冲首先经过光栅展宽后再注入到再生脉冲,然后进行放大.注入的种子脉冲能量为1nJ,再生腔为平凹腔,R 为4m,腔长为1.65m.再生放大器的实验结果如图所示.     

双程放大740 mJ TEC冷却LD泵浦Nd:YAG激光器

报道了一种实现高能量输出的激光二极管（LD）泵浦无水冷全固态Nd：YAG双程放大器结构。整个放大系统采用了泵浦与晶体棒集成的模块以及半导体制冷器（TEC）,从而实现了激光系统的小型化。总腔长为730 mm。在10 Hz重复频率下,主振荡器得到了最大脉冲能量为350 mJ的激光输出。脉宽为9.7 ns,光束质量M²在两个方向分别为7.7和12.3。并进行了双程放大的研究,双程放大后得到了740 mJ、10 ns的激光输出。     

全固态kHz啁啾脉冲飞秒激光放大器

要建造大功率超强激光系统,必须将nJ量级的种子进行放大,以得到mJ量级以及更高能量的激光输出.为达到这个目的,必须使种子能量指数增加,再生腔放大器是实现这一目的的良好途径;同时,为了得到更稳定的激光输出,须采用高重复频率的泵浦源.为此,设计了一种kHz重复频率激光泵浦的再生放大器,使用15 mJ的527 nm的绿光泵浦,得到了约2.3 mJ的800 nm放大激光输出,同时,对其输出激光的光谱特性进行了测量,将带宽为40 nm的种子注入后,得到了光谱带宽约为30 nm激光输出.     

输出能量4mJ的1kHz飞秒掺钛蓝宝石激光再生放大研究

针对高能量千赫兹重复频率飞秒激光的应用需求,设计了一套采用线性再生腔结构的高效率飞秒钛宝石激光啁啾脉冲放大系统.通过优化腔型设计,在重复频率为1 kHz、单脉冲能量为20 mJ的527 nm激光抽运下,将展宽后的800 nm啁啾脉冲激光的能量放大到5.8 mJ,对应斜效率达到30.7%.进一步通过色散补偿压缩脉冲宽度,获得了单脉冲能量为4 mJ、脉冲宽度为45.7 fs的输出,稳定性测量表明激光的能量抖动仅为0.18%(均方根值).     

18mJ,100Hz飞秒钛宝石激光放大器

采用环形腔再生放大及四通放大的两级放大方案,在重复频率100Hz、单脉冲能量75.1mJ的倍频Nd:YAG激光抽运下,通过啁啾脉冲放大飞秒钛宝石激光,获得了单脉冲能量25.4mJ的放大输出,对应能量转换效率33.8%.经光栅压缩器补偿色散后的单脉冲能量为18.3mJ,脉冲宽度为37.8 fs,对应峰值功率0.48 TW.测量其脉冲能量稳定性为3.6%,光束质量M~2因子在X和Y方向上分别为1.8,1.6.     

大能量输出类再生放大系统研究

在对再生放大系统进行改进的基础上提出类再生放大技术,应用大口径放大器,在腔内增加完全成像系统,对注入整形光束进行任意多次的保形放大。可行性验证实验基于两个低增益、大口径放大器,已达到大于10~4的系统增益;在注入能量仅为43μJ能量条件下,实现了大于600 mJ的系统输出能量。验证实验结果表明基于较低增益放大器单元的类再生放大系统,既能实现高增益又能实现大能量输出。     

用钛宝石再生放大器产生高重复率啁啾脉冲列

针对啁啾脉冲放大技术建成的钛宝石激光装置，提出一种获得高重复率激光脉冲列的方法.通过改变钛宝石再生放大器中泡克耳斯盒电光开关的传统工作模式，使得腔内放大的脉冲从某特定时刻起，每当在腔内往返一次就以一定的倒出比例（倒出率）倒出腔内脉冲能量的一部分，从而可以在有限的时间段内产生高重复率的啁啾激光脉冲列.基于Franz-Nodvik放大理论，建立了该高重复率再生放大器的理论模型，通过数值计算，系统地分析了初始增益、倒出时刻、倒出率对输出的脉冲序列的影响.在抽运功率为35mJ、倒出率为1/2的实验条件下，通过腔外的脉冲数量选择器，在一个抽运周期内的有限时间段内已获得了14个幅度相近、单脉冲能量约为0.02mJ、重复率为100MHz的啁啾脉冲序列.从此啁啾脉冲列中选取数个脉冲，通过10TW级的激光系统放大和压缩，已获得100MHz重复率的飞秒太瓦级脉冲列. 关键词： 高重复率 多通放大 啁啾脉冲放大 钛宝石激光器     

激光二极管列阵抽运的单纵模激光脉冲再生放大器

详细研究了单纵模激光脉冲从注入到再生放大过程中脉冲的建立过程 ,采用折迭驻波腔结构的再生放大器 ,实现了激光二极管列阵抽运的高稳定单纵模激光脉冲的再生放大 ,获得了总增益为 1 2× 10 7的高增益放大。取出单脉冲能量为 1 2mJ ,单程净增益为 1 5。     

Ti:sapphire Regenerative Amplifier at 1.056 μm

The design and performance of a Ti:sapphire regenerative amplifier operating at 1. 056 μm are described. A laser pulse with an initial pulsewidth of 100 fs is amplified to ≥1.5 mJ in the amplifier after firstly stretched to 850 ps. The amplified pulse can be re-compressed to ～300 fs with energy of ～1 mJ. Loss of the spectrum happens in the regenerative cavity since bandwidth of the coat of optics in the cavity is not enough adequate.     

Picosecond laser system with 30-W average power via cavity dumping and amplifying

We present a picosecond laser system with high energy by technologies of cavity dumping and amplifying. Firstly, pulses with 10 ps and ～520 nJ were obtained by cavity-dumped mode-locked laser at 10 kHz repetition rate. Secondly those pulses were seeded into a side-pumped regenerative amplifier (RA). Then pulses output from the regenerative amplifier were amplified by two four-pass post amplifiers. From the laser system pulses with an average power of 30 W corresponding to 3 mJ pulse energy were achieved with the pulse-width of 25.4 ps at repetition rate of 10 kHz.     

Efficient generation of 200 mJ nanosecond pulses at 100 Hz repetition rate from a cryogenic cooled Yb:YAG MOPA system

A diode-pumped Master Oscillator Power Amplifier (MOPA) laser system based on cryogenic cooled Yb:YAG has been designed, developed and its output performance characterised. The laser system consists of a fibre oscillator, an active mirror regenerative amplifier and a four pass main amplifier. 2.4 mJ, 10 ns, 100 Hz seed pulses from the fibre oscillator/regenerative amplifier arrangement were amplified up to pulse energies of over 200 mJ by using the four pass main amplifier arrangement. As a further study we have obtained an increased slope efficiency of 40% and an optical-to-optical efficiency of 30% using a pinhole vacuum spatial filter/image relay for laser mode control. With 1.8 mJ input seed pulses, output pulse energies of around 150 mJ were achieved.     

All-fiber laser seeded femtosecond Yb:KGW solid state regenerative amplifier

A high efficiency compact Yb:KGW regenerative amplifier using an all-fiber laser seed source was comprehensively studied. With thermal lensing effect compensated by the cavity design, the compressed pulses with energy of 1 m J at 1 k Hz and 0.4 m J at 10 k Hz in sub-400-fs pulse duration using chirped fiber Bragg grating(CFBG) stretcher were demonstrated.A modified Frantz–Nodvik equation was developed to emulate the dynamic behavior of the regenerative amplifier. The simulation results were in good agreement with the experiment. Numerical simulations and experimental results show that the scheme can be scalable to higher energy of multi-m J, sub-300 fs pulses.     

无展宽器的高重复率钛宝石啁啾飞秒脉冲再生放大器的研究

通过优化放大腔结构参数和采用高光束质量的泵浦激光,依靠放大器腔内各个元件的色散展宽种子脉冲, 用钛宝石作为增益介质, 在低泵浦能量下, 实现了高光束质量,高稳定的中等能量的高重复率飞秒脉冲再生放大. 将钛宝石晶体离焦放置,有效的避免了光学损伤. 在1.1 mJ的绿光泵浦下, 获得了2 ps, 120 μJ, 重复频率为1 KHz, 光谱带宽7.8 nm的放大脉冲, 用石英棱镜对压缩可得到130 fs的激光脉冲.