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1.
研究了周期量级的圆偏振激光在空气中成丝产生太赫兹辐射的偏振特性。将中心波长1.8 m、脉宽8.6 fs 的圆偏振红外激光脉冲聚焦到空气中,形成等离子体细丝,产生太赫兹辐射。通过测量太赫兹辐射的偏振状态,和偏振方向与驱动激光载波-包络相位的关系,发展太赫兹波偏振控制的方法。实验结果表明,太赫兹辐射为椭圆偏振,而且偏振平面随着驱动激光载波-包络相位的变化而转动。这对太赫兹波的偏振控制有重要意义,并为周期量级激光载波-包络相位的测量提供了新方法。  相似文献   

2.
飞秒光学频率梳在精密计量学和光谱学中扮演着革命性的推动角色,成为近二十年超短脉冲激光技术及应用研究领域最活跃的前沿方向之一。文中基于250 MHz重复频率(frep)的掺镱(Yb)光纤激光器,研究了不同腔内色散以及锁模机制对飞秒脉冲序列载波包络相位偏移频率(fCEO)噪声的影响。通过对飞秒光梳细节的优化,得到了49 dB信噪比的fCEO拍频信号并获得了秒稳3.210-10的锁定结果,同时frep的锁定结果也达到了到了秒稳3.410-13的精度。此外文中还研究了不同啁啾状态的种子光飞秒脉冲对基于大模场面积双包层Yb光子晶体光纤放大器输出光脉冲宽度的影响。以携带-3.8104 fs2预啁啾量的光脉冲作为种子光,在60 W 976 nm半导体激光泵浦下,获得了250 MHz重复频率、23 W平均功率和66 fs压缩后脉冲宽度的激光输出。  相似文献   

3.
本文通过求解含时薛定谔方程,研究了双色激光场中驱动脉冲相位从0~1.9π时产生的高次谐波,并且该双色场由9fs/1600nm基波脉冲和较弱的6fs控制脉冲合成.在截止区域,可以通过改变驱动脉冲的相位来控制平台的宽度.从而获得带宽为499eV的超宽超连续谱谐波谱,并且通过傅立叶变换可以获得超短的3.8as的阿秒脉冲.而且为了深入了解物理机制,还进行了量子电离和时频分析.  相似文献   

4.
于洪 《激光技术》2013,37(5):679-681
为了快速准确地测量飞秒激光脉冲宽度,采用二阶自相关方法,设计了用于测量飞秒激光脉冲宽度的测量系统。结果表明,通过自主设计的系统测得800nm种子激光脉冲宽度为217.6fs,而利用Coherent公司生产的单脉冲自相关仪测得脉冲宽度为199.51fs,两者误差仅为0.43%。由此可见,自主设计的测试系统可以对飞秒激光脉冲宽度进行准确测量。  相似文献   

5.
脉冲相位共轭光研究的进展   总被引:4,自引:2,他引:2  
近年来,随着超短脉冲激光技术的迅速发展,脉冲相位共轭技术,尤其是fs脉冲相位共轭技术,愈来愈受到重视。本文综述了脉冲相位共轭,包括ns,ps和fs相位共轭研究的进展。  相似文献   

6.
利用块状介质进行飞秒强激光脉冲的腔外压缩   总被引:1,自引:0,他引:1  
高强度飞秒激光脉冲的腔外压缩是获得高次谐波阿秒脉冲驱动源的必要手段.实验研究了超强超短飞秒激光脉冲在经过块状介质后的光谱展宽和色散补偿压缩现象.单脉冲能量0.26 mJ,脉宽50 fs的激光脉冲经透镜在空气中聚焦后再入射到块状材料上,出射脉冲光谱被展宽到接近40 nm.由于在块状材料中的自聚焦效应,出射光束质量变好并保持较小的空间啁啾.利用熔融石英棱镜对补偿带有正色散的出射脉冲,最后得到>0.1 mJ,19 fs的压缩脉冲.利用SPIDER装置测量了出射脉冲的脉宽和光谱相位.整个系统的能量效率大约为35%,压缩后的激光脉冲具有很好的空间分布和平滑的时域包络.实验结果实现了利用块状材料对飞秒激光脉冲的腔外压缩,这种方法将适用于对更高能量飞秒脉冲的压缩.  相似文献   

7.
采用全量子非微扰散射理论,研究了周期量级微波频率激光脉冲中高激发里德堡态铷原子光电离的不对称现象。发现了光电子角分布的不对称性,这一不对称性由电离过程中不同跃迁通道之间的干涉引起。讨论了光电子角分布的不对称性对载波-包络(Carrier-Envelo?pe , CE)相位、脉冲宽度及光电子能量的依赖性,发现光电子角分布的不对称性随CE相位、脉冲宽度及光电子能量的变化有显著变化。这一研究证实了最近的实验观测,为微波频率光学范畴内CE相位的测量及光电子角分布的控制提供了一种有效的方法。  相似文献   

8.
频率分辨光学开关法测量飞秒脉冲   总被引:1,自引:1,他引:1  
阐述了频率分辨光学开关法测量飞秒脉冲的原理,详细分析了模式尺寸效应和非线性效应对飞秒脉冲测量的影响.构建了一台用于飞秒脉冲测量的二次谐波-频率分辨光学开关装置,利用该装置对谐振腔输出的飞秒脉冲及压缩后的脉冲进行了测量.得到了飞秒脉冲的时间宽度及光谱宽度、电场及其相位在时域和频域的详细信息.谐振腔直接输出脉冲的时间宽度为56 fs,光谱宽度为27 nm,时间带宽积为0.686,算法中的最小误差为0.001792.脉冲压缩后的测量结果为27 fs,光谱宽度为92 m,时间带宽积为1.27,算法误差为0.0093289.  相似文献   

9.
高能量低重复频率超短激光脉冲的测量   总被引:2,自引:0,他引:2  
利用非线性晶体 (BBO)的非共线匹配倍频效应 ,研制了实时测量高能量低重复频率超短激光脉冲宽度的单脉冲自相关仪 ,并对飞秒 (fs)参量放大器的输出脉冲宽度进行了测量 ,测得了 10 3fs的超短激光脉冲宽度。  相似文献   

10.
研究了两台独立运转的掺镱光纤飞秒激光器的脉冲序列与载波包络相位同步。使用平衡光学互相关的方法探测两台激光器的脉冲延迟,控制腔内高速压电陶瓷以锁定两台激光器的重复频率,得到两台激光器的剩余相对时间抖动为380as。不同的重复频率锁定带宽会对载波包络相位信号产生明显的影响,相比于使用压电陶瓷(低锁定带宽),使用电光调制器锁定重复频率(高锁定带宽)会使载波包络相位产生额外的噪声。将两台激光器的输出脉冲在空间上重合,入射进入平衡探测器,探测到两台激光器的相对载波包络频率信号。使用腔外声光调制器对两台激光器的载波包络相位进行锁定,得到两台激光器的剩余相位噪声为495mrad。锁定后观测到两激光器的光谱干涉,为相干脉冲合成奠定基础。  相似文献   

11.
A wavelength-tunable 3.5 ps pulse generator, which employs an electroabsorption modulator (EAM), a fibre pulse compressor, and a self-phase-modulation (SPM)-based pulse reshaper, is developed. An EAM directly generates 21 ps pulses at a repetition rate of 10 GHz, which are compressed to 6 ps by a fibre pulse compressor. An SPM-based pulse reshaper then eliminates the large pedestal of the compressed pulses. Thus, 3.5 ps pulses with extinction ratio larger than 27 dB and timing jitter as small as 150 fs are obtained.  相似文献   

12.
The compression characteristics at femtosecond durations are compared for dispersion-decreasing fibers (DDF's) constructed out of standard step index fibers and fibers designed to have low third-order dispersion (dispersion-flattened fibers). It is shown that the dispersion slope of a standard fiber causes the compressed pulse spectrum to vary substantially with wavelength. Furthermore, the peak of the compressed pulse spectrum can appear in a different wavelength band than the input pulse. Both of these problems are substantially reduced by using a dispersion-flattened DDF. The compression of 3-3.6-ps pulses to durations less than 180 fs was achieved between 1533-1565 nm at a repetition rate of 10 GHz. The shortest pulses obtained were 98 fs with peak-to-pedestal ratios in excess of 20 dB  相似文献   

13.
7.5-ps optical pulses generated from a gain-switched semiconductor laser at 2 GHz are successfully compressed down to 20 fs using a four-stage fiber soliton pulse compressor consisting of standard single-mode transmission, Er-doped, dispersion-decreasing, and dispersion-flattened fibers, respectively. We have experimentally confirmed that the soliton self-frequency shift plays an important role in obtaining such high compression in very short fibers, and also in minimizing the inherent undesirable pedestal component  相似文献   

14.
We report the generation of high-power ultrashort bound states of three pulses in an ytterbium-doped double-clad fiber laser. The laser is mode-locked through nonlinear polarization rotation technique in a unidirectional cavity configuration. A pair of diffraction grating is incorporated in the cavity to compensate for the normal dispersion of the fiber. The laser generates chirped bound states of three pulses with either equal or different time separations, with more than 500-pJ energy per pulse. These pulses are subsequently compressed to 100 fs with a compression factor of more than 40.  相似文献   

15.
为了获得更高的时间分辨率,更短的飞秒脉冲,采用双棱镜和一个平面镜结构对飞秒激光脉冲进行腔外压缩,构建了一台二次谐波频率分辨光学开关装置,对谐振腔输出的飞秒脉冲及压缩后的脉冲进行了测量,取得了脉冲压缩前和压缩后的实验数据,压缩前脉冲的宽度为89fs,脉冲的时间带宽积为0.9096,误差为2.4‰,输入脉冲的平均功率约为480mW;脉冲压缩后的测量结果为22fs,光谱宽度为43nm,时间带宽积为0.44203,误差为1.1‰,压缩脉冲的平均功率约为250mW.压缩比为4:1,高于有关文献的报道.结果表明,该装置实现了飞秒脉冲腔外压缩,对获得更短的飞秒脉冲是有帮助的.  相似文献   

16.
Otoh  H. Sudo  S. Okamoto  K. Hosaka  T. 《Electronics letters》1988,24(13):785-786
Optical pulse compression at 1.5 μm has been conducted. 20 ps (FWHM) optical pulses from a Tl:KCl-colour-centre laser were compressed into pedestal-free 1.2 ps pulses using a large-positive-dispersion fibre and a grating pair. In addition, 280 fs pulses were obtained from the resultant 1.2 ps through the soliton compression effect in a negative-dispersion fibre  相似文献   

17.
超快电磁脉冲辐射的产生与检测   总被引:2,自引:0,他引:2  
吴克勤  周炯 《电子学报》1997,25(9):60-63
本文报道了一种产生超快电磁脉冲辐射并对其进行检测的方法。利用飞秒级超快激光脉冲照射半导体样品,并通过采用一种特殊结构电光采样进行接收,我们测得了脉宽为300飞秒的电磁脉冲辐射。  相似文献   

18.
The group velocity dispersion of a multilayer thin film Gires-Tournois interferometer used for reflection of ultrashort optical pulses can be continuously tuned from positive to negative values at an extremely low loss in pulse energy. Thus, this device can be applied for compression of femtosecond pulses independent of the sign of the frequency chirp by simple angle tuning of the interferometer. This has been demonstrated with up-chirped 210 fs pulses which have been compressed to an almost transform-limited duration of 115 fs.  相似文献   

19.
文章利用脉冲对的交叉相位调制(XPM)效应和非线性掺铒光纤放大环镜(ED -NALM)的整形放大作用,提出了一种对无啁啾高斯脉冲进行脉冲压缩的设计方案.数值模拟的结果表明,利用此方案可将脉宽为10 ps、中心波长为1 553 nm的无啁啾高斯脉冲压缩成脉宽为150 fs的无基座超短脉冲,且脉冲得到了很好的放大.  相似文献   

20.
A wavelength-tunable passively-mode-locked semiconductor laser source of subpicosecond pulses is demonstrated. The system includes a two-section multiple-quantum-well laser which is coupled to an external grating for tuning and is followed by an external grating pair for pulse compression. A tuning range of 16 nm round 846 nm is obtained, resulting in compressed pulse widths as short as 260 fs and pulse widths shorter than 600 fs for all wavelength values within this tuning range. Time-bandwidth products are one to two times the transform limit  相似文献   

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