共查询到20条相似文献,搜索用时 370 毫秒
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自锁模Cr:LiSAF激光器的实验研究 总被引:2,自引:1,他引:1
以功率为900mW,波长为488nm的单线氩离子激光作为泵浦源,在腔内不加任何主动调制器和可饱和吸收体的情况下实现了Cr:LiSAF激光器的飞秒级自锁模运转,得到了脉冲宽度为40fs,重复频率为100MHz,平均输出功率为45mW的稳定的锁模脉冲序列。 相似文献
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评述了飞秒光脉冲研究的现状,其包括同步泵浦连续染料激光器、对碰锁模环形染料激光器、飞秒光脉冲的多级放大和超短光脉冲的压缩. 相似文献
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在自锁模飞秒钛宝石激光器运转状态不变的条件下,仅仅改变所加光阑,便可获得三波长或双波长的飞秒光脉冲运转.在此基础上,我们比较了这两种运转状态下激光器输出脉冲的脉宽,啁啾、中心波长间距和输出功率的差异.给出了在不同条件下运转时的双波长激光器的输出特性.讨论了多波长运转时的一些规律. 相似文献
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双腔双波长交叉锁模钛宝石飞秒激光器的研究 总被引:3,自引:0,他引:3
本文建立了一台双光束泵浦的双腔双波长交叉锁模Ti:Sapphire激光器,实现了中心波长为755nm和845nm的双波长同步锁模输出,得到了脉宽分别为28fs和34fs的锁模脉冲. 相似文献
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High power femtosecond pulses in the Vacuum Ultra Violet (VUV) have been generated through the nonlinear interaction of femtosecond KrF pulses with xenon and argon gas. Under near resonant two photon excitation of xenon by a femtosecond KrF laser, parametric four wave mixing processes lead to VUV pulses at 147 and 108 nm with pulse energies in the 10 µJ range. Tuning is demonstrated by mixing the KrF pulse with a 500 fs dye laser pulse at 497 nm, resulting in 165 nm emission. In argon, a three photon resonance leads to third harmonic generation at 83 nm and micro joule level pulses near 127 nm generated by a six wave mixing process. Since the spectra of the VUV pulses show an ionization-induced blue shift with increasing KrF laser intensity, the VUV pulses can be shown to have temporal duration less than the pulse width (450 fs) of the KrF laser. Blue shifting of the third harmonic of the KrF laser in argon is dominated by a reduction in the neutral gas density rather than by an increase in the electron density. 相似文献
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孤立阿秒脉冲因可以跟踪和控制原子及分子内电子的运动过程而备受关注.本文从理论上开展了氦原子在3束飞秒脉冲激光组合场辐照下产生的高次谐波和阿秒脉冲辐射的研究.组合激光场由16 fs/1600 nm,15 fs/1100 nm和5.3 fs/800 nm的钛宝石脉冲构成.与前两束脉冲合成的双色场产生谐波谱相比,附加钛宝石脉冲的三色场产生的高次谐波发射谱呈现出高转换效率及宽带超连续特性,超连续谱范围覆盖从230—690次谐波,傅里叶变换后实现了128 as高强度孤立短脉冲的产生.该结果归因于合成的三色场呈现出高功率及少周期的中红外飞秒脉冲激光特性,可以有效控制原子电离以及复合发生在中红外飞秒脉冲的一个有效光学周期内. 相似文献
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<正>Two operating modes,independent self-mode-locking and cross-mode-locking,are presented in a two-beampumped double-cavity dual-wavelength femtosecond Ti:sapphire laser.Synchronization of femtosecond and picosecond laser pulses is achieved by properly adjusting the cavity length matching and distributing the pump laser powers in the two laser cavities,and moreover,a timing jitter of 517 fs between femtosecond and picosecond pulses is obtained,with wavelength tuning ranges around 36 and 22 nm in the femtosecond and picosecond cavities,respectively. 相似文献
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McWilliam A Lagatsky AA Brown CT Sibbett W Zhukov AE Ustinov VM Vasil'ev AP Rafailov EU 《Optics letters》2006,31(10):1444-1446
A quantum-dot-based saturable absorber has been demonstrated to initiate the generation of femtosecond pulses from a passively mode-locked solid-state laser. Control and tuning of the pulse duration from 58 ps to 158 fs was achieved. The 158 fs transform-limited pulses at 1280 nm are the shortest pulses that were produced from the Cr:forsterite laser passively mode locked by an InAs/InGaAs quantum-dot semiconductor saturable absorber mirror. 相似文献
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S. Canulescu E. Papadopoulou D. Anglos T. Lippert M. J. Montenegro S. Georgiou M. D?beli A. Wokaun 《Applied Physics A: Materials Science & Processing》2011,105(1):167-176
Thin films of La0.6Ca0.4CoO3 were grown by pulsed laser ablation with nanosecond and femtosecond pulses. The films deposited with femtosecond pulses (248 nm,
500 fs pulse duration) exhibit a higher surface roughness and deficiency in the cobalt content compared to the films deposited
with nanosecond pulses (248 nm, 20 ns pulse duration). The origin of these pronounced differences between the films grown
by ns and fs ablation has been studied in detail by time-resolved optical emission spectroscopy and imaging. The plumes generated
by nanosecond and femtosecond ablation were analyzed in vacuum and in a background pressure of 60 Pa of oxygen. The ns-induced
plume in vacuum exhibits a spherical shape, while for femtosecond ablation the plume is more elongated along the expansion
direction, but with similar velocities for ns and fs laser ablation. In the case of ablation in the background gas similar
velocities of the plume species are observed for fs and ns laser ablation. The different film compositions are therefore not
related to different kinetic energies and different distributions of various species in the plasma plume which has been identified
as the origin of the deficiency of species for other materials. 相似文献
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Generation of wideband tunable femtosecond laser based on nonlinear propagation of power-scaled mode-locked femtosecond laser pulses in photonic crystal fiber 下载免费PDF全文
《中国物理 B》2021,(4)
We implement an experimental study for the generation of wideband tunable femtosecond laser with a home-made power-scaled mode-locked fiber oscillator as the pump source.By coupling the sub-100 fs mode-locked pulses into a nonlinear photonic crystal fiber(NL-PCF),the exited spectra have significant nonlinear broadening and cover a spectra range of hundreds of nm.In experiment,by reasonably optimizing the structure parameters of NL-PCF and regulating the power of the incident pulses,femtosecond laser with tuning range of 900-1290 nm is realized.The research approach promotes the development of femtosecond lasers with center wavelengths out of the traditional laser gain media toward the direction of simplicity and ease of implementation. 相似文献
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《中国科学:物理学 力学 天文学(英文版)》2010,(6)
The ultrafast dynamics of o-fluorophenol via the excited states has been studied by femtosecond time-resolved photoelectron imaging. The photoion and photoelectron spectra taken with a time delay between 267 nm pump laser and 800 nm probe laser provide a longer-lived S1 electronic state of about ns timescale. In comparison,the spectra obtained by exciting the S2 state with femtosecond laser pulses at 400 nm and ionizing with pulses at 800 nm suggest that the S2 state has an ultrashort lifetime about 102 fs and reflects the internal conversion dynamics of the S2 state to the S1 state. 相似文献
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超宽带近红外和蓝光飞秒激光脉冲产生的实验研究 总被引:3,自引:3,他引:0
增益介质中泵浦光束提供的软光阑效应对于实现克尔透镜稳定锁模及其超宽带光谱脉冲的产生具有非常重要的作用.实验上首先对半导体泵浦全固化钛宝石飞秒激光器的锁模动态特性进行了研究,在4 W绿光泵浦状态下获得了平均输出功率为570 mW、中心波长在794 nm~835 nm范围内调谐、光谱带宽最大可达135 nm的近红外光脉冲输出,其相应的时域变换极限脉冲宽度均小于10 fs.另外,将光束聚焦在超薄BBO晶体上,获得了中心波长在418 nm~429 nm之间调谐、光谱宽带时域变换极限小于15 fs的蓝光飞秒脉冲. 相似文献
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Subpicosecond pulses at a fixed wavelength produced with a low-Q cavity dye laser pumped by a single, nanosecond laser (Q-switched Nd:YAG) are converted into tunable high-power sub-100 femtosecond pulses by generation, spectral selection, amplification and compression of a supercontinuum. The tunable, chirped, high-energy pulses obtained are compressed with a prism pair. Energies up to 50 J in sub-100 fs pulses were obtained in the 540 to 650 nm range using 40 mJ of the Nd: YAG-laser pumping pulses at 532 nm. The whole sub-100 fs system including the low-Q dye laser uses only one Nd:YAG laser as a pump source. 相似文献