共查询到20条相似文献,搜索用时 15 毫秒
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Yang Yashuai Li Yongliang Wang Chi Sun Xiaoting 《Journal of Russian Laser Research》2022,43(3):389-395
Journal of Russian Laser Research - We propose an autocorrelator based on noncollinear second-harmonic generation effect and a pulse-width measurement program written by LabVIEW software providing... 相似文献
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高效全固化紫外四倍频激光器的研究 总被引:7,自引:0,他引:7
用半导体激光器抽运的调Q YLF倍频激光器抽运掺钛蓝宝石激光器,用LBO晶体在腔内产生二次谐波,再聚焦到BBO晶体上产生四次谐波深紫外激光。为了提高谐波转换效率,在腔内分别插入了单片、组合双折射滤光片和聚焦透镜,在平均功率为3.6W,波长为527nm的抽运光下得到410mW,417nm的蓝光。用长焦距的透镜聚焦二次谐波,得到34mW,208nm的紫外脉冲激光。从实验上详细研究了基频光的线宽对二次谐波效率的影响,二次谐波的线宽对四次谐波效率的影响、基频光的波长对四次谐波产生效率的影响。全面地分析了单片和组合大拆射滤光片及抽运功率对钛蓝宝石激光器基频光的脉宽、线宽等参量的影响。 相似文献
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Carrier Envelope Phase Controlled High-Order Harmonic Generation in Ultrashort Laser Pulse 下载免费PDF全文
We investigate the carrier envelope phase (CEP) effects on high-order harmonic generation (HHG) in ultrashort pulses with the pulse duration 2.5 fs when the laser intensity is high enough so that the initial state is ionized effectively during the laser pulse but remains about 20% population at the end of the laser pulse. We find that the ionization process of the initial state is very sensitive to the CEP during the laser pulse. The ionization process of the initial state determines the continuum state population and hence influences dramatically the weights of the classical trajectories that contribute to HHG. In such a case we can not predict the cutoff and the structure of the harmonic spectrum only by the number and the kinetic energy of the classical trajectories. The harmonic spectrum exhibits abundant characters for different CEP cases. As a result, we can control the cutoff frequency and the plateau structure of the harmonic spectrum with CEP by controlling the time behaviour of the ionization of the initial state. 相似文献
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《理论物理通讯》2017,(1)
Molecular harmonic spectra of H+2driven by the linearly polarized laser pulses with different polarized angles have been theoretically investigated through solving the two-dimensional time-dependent Schr¨odinger equation.(i) Below-threshold harmonic spectra show a visible enhanced peak around the 7th harmonic(H7), which produces a red-shift phenomenon as the internuclear distance increased. Theoretical analyses show the red-shift enhanced peak is caused by the laser-induced electron transfer between the ground state and the 1st excited state of H+2.(ii) Due to the two-centre interference phenomenon, the above-threshold harmonic spectra exhibit many maxima and minima.(iii)With the introduction of the polarized angle, the anomalous elliptically polarized harmonics can be found. But, with the introduction of the spatial inhomogeneous effect, not only the ellipticities of the harmonics are equal to a stable value of ε~ 0.1–0.3, but also the harmonic cutoffs are extended. As a result, four super-bandwidths of 407 e V, 310 e V,389 e V, and 581 e V can be obtained. Time profiles of the harmonic generations have been shown to explain the harmonic characteristics. Finally, a series of elliptically polarized(ε~ 0.1–0.3) attosecond X-ray pulses with durations from 18 as to 25 as can be directly produced through Fourier transformation of the spectral continuum. 相似文献
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介绍了一种能够直接检测飞秒脉冲啁啾大小的方法。采用共轴结构的迈克尔逊干涉自相关二次谐波检测系统对自制碰撞脉冲锁模循环染料激光器输出的最窄脉冲宽度约为200fs的脉冲进行了测量。测得的飞秒脉冲自相关二次谐波曲线表明:实测曲线的下包络两翼明显隆起,包络外形很不整齐,对称性较差,说明光脉冲含有啁啾。通过比较干涉测量曲线和理论曲线的形状与面积的大小,可以直观地反映出光脉冲所含啁啾的大小。实验结果分析表明,利用满足光相关检测所需精度的光学元件和满足光相关探测基本条件的实验装置,能测得含有相位及啁啾信息的快干涉项信号,是一种能够直观检测光脉冲所含啁啾大小的可行方法。 相似文献
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双波长双脉冲激光三次谐波的产生方法 总被引:1,自引:0,他引:1
提出双波长双脉冲激光产生三次谐波的方法。波长不同的两脉冲激光束由反射使它们合拢后通过两块非线性的BBO晶体 ,激光脉冲第一次通过BBO晶体产生两波长的二次谐波 (SHG) ,它们由各自的反射镜反射再次通过BBO又产生了二次谐波 ,这两次产生的二次谐波和基波通过用于产生三次谐波的BBO晶体可产生双波长的三次谐波 ,它们由 45°斜置的耦合镜输出。文中分析了满足二次谐波和三次谐波的四个相位匹配的条件 ,该方法也可用于腔内双波长双脉冲的三次谐波激光的产生 ,给出了相应的实验结果。 相似文献
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强激光与一维多原子分子离子的相互作用及高次谐波的增强 总被引:1,自引:1,他引:0
研究强激光脉冲与一维多原子分子离子的相互作用,讨论双色激光场中高次谐波转化效率的提高,并应用经典三步模型说明高次谐波平台展宽的物理机制. 相似文献
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Russian Physics Journal - Results of investigation of conversion of radiation with the wavelength λ = 950 nm and pulse duration of 100 ps into the second harmonic are reported. It is... 相似文献
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LI Xuexin LIU Yaqing ZHAI KanXU Zhizhan HAN Shensheng 《Chinese Journal of Lasers》1997,6(6):539-542
EfectsofPulseDurationsonHighorderHarmonicGenerationLIXuexinLIUYaqingZHAIKanXUZhizhanHANShensheng(ShanghaiInstituteofOpticsan... 相似文献
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基于在正常色散渐减光纤(ND-DDF)或者正常色散光纤放大器,获得线性啁啾抛物线脉冲,提出并分析了利用ND-DDF放大器获得线性啁啾抛物线脉冲的优化方案.数值研究结果表明:与用ND-DDF或者正常色散光纤放大器获得线性啁啾抛物线脉冲的方案相比,利用ND-DDF放大器获得的抛物线脉冲的线性啁啾更为明显;研究还发现,增益影响着线性啁啾的大小和质量.计算表明,利用ND-DDF放大器产生的抛物线脉冲经啁啾补偿后可获得更大的压缩因子和更高的峰值功率. 相似文献
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Influence of Initial Pulse Chirp on Rainbow-Like Supercontinuum Generation from Filamentation in Air 下载免费PDF全文
Supereontinuum (SC) generation from laser filamentation in air is found to depend strongly on the pulse duration. Rainbow-like SC generation is observed only for a pulse of appropriate negative chirp that agrees with the predictions put forward by Golubtsov et al. [Quantum Electron. 33 (2003) 525]. The conversion efficiency of an 800-nm laser light to rainbow-like SC is found to be the highest for 257fs pulses with an initial negative chirp. A larger chirp will lead to filamentation surviving at longer distance. 相似文献
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非线性附加耦合腔产生超短激光脉冲 总被引:1,自引:0,他引:1
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,首次给出了该锁模激光系统在瞬态平衡时输出脉宽的具体表达式,实验测量结果与理论计算值相比吻合得很好;最后,文中还报道了有关实验参量与该锁模激光系统输出特性的关系曲线。 相似文献
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提出了主动锁模联合非线性偏振旋转光纤激光器中基于偏振控制器的脉宽可调平顶光脉冲生成技术.光纤激光器由主动锁模部分和一根掺Bi的高非线性光纤联合两个偏振控制器及光纤检偏器构成的非线性偏振旋转结构组成.分析了该实验装置在不同状态下的工作机制,通过调节激光器中的两个偏振控制器,实验获得了10GHz的脉宽可调平顶光脉冲,脉宽调节范围在12~19ps之间,调节激光腔中的宽带滤波器,可在不同波长处获得平顶光脉冲.实验表明:输出的平顶光脉冲性能稳定,边模抑制比为65dB,定时抖动145fs. 相似文献
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By applying a small frequency detuning to the RF modulation frequency, pulse trains with repetition rates of integer multiples of the RF modulation frequency have been obtained in an actively mode-locking fiber ring laser. Optical pulse trains with repetition rates of 20 GHz, 30 GHz and 40 GHz were generated respectively here. Furthermore, an interesting phenomenon of generation of pulse train with repetition rate half the modulation frequency was observed. 相似文献
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Effect of pulse slippage on resonant third harmonic generation of a short pulse laser in electron-hole plasma in the presence of wiggler magnetic field has been investigated. The group velocity mismatch of the third harmonic pulse and the fundamental pulse is significant in electron hole plasma. As the third harmonic pulse has higher group velocity than that of fundamental pulse, therefore, it moves faster than the fundamental pulse. It gets slipped out of the domain of fundamental pulse and its amplitude saturates. Phase matching condition is satisfied by applying wiggler magnetic field,which provides additional angular momentum to the third harmonic photon to make the process resonant. Enhancement in the efficiency of third harmonic generation of an intense short pulse laser in electron-hole plasma embedded with a magnetic wiggler is seen. 相似文献
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We theoretically investigate high-order harmonic and isolated attosecond pulse generation in a two-color chirped laser field,which is synthesized by a 9 fs/800 nm fundamental chirped pulse and a 9 fs/1600 nm controlling chirped pulse.Our numerical results show that,by using this method,not only is the harmonic cutoff significantly extended to the 948th order harmonic,but also the bandwidth of the supercontinuum spectrum is effectively broadened to about 1342 eV.In addition,due to the introduction of the chirp,the long quantum path is suppressed and only the short one is selected,and then an isolated 28 as pulse with a bandwidth of 155 eV is obtained directly. 相似文献