共查询到16条相似文献,搜索用时 139 毫秒
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我们实验上发展了基于飞秒激光旋转相干光谱的整形飞秒激光转动动力学调控方法,通过脉冲整形技术调控激发脉冲的光谱相位,从而实现对飞秒激光作用下转动态相干激发过程中复原信号及转动布居数的调控. 研究了飞秒激光旋转相干光谱对激光频谱相位的响应机制,突出了飞秒激光频谱相位在气相分子转动态相干激发中的重要作用. 为飞秒激光作用下生物大分子和团簇鉴别及结构探测研究提供了新的参考. 相似文献
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利用基于液晶空间光调制器的飞秒激光脉冲整形技术,对飞秒激光在熔融石英中形成等离子体丝的过程进行优化控制研究。实验结果表明:通过脉冲整形可以在固体介质中的指定位置产生等离子体丝。实现了整形脉冲在熔融石英中成丝起点的长距离可控移动,最大移动量达到5.4 mm。通过求解(3+1)维非线性薛定谔方程,对整形脉冲在熔融石英中的成丝过程进行理论模拟研究,得到了与实验一致的结果。研究结果表明:等离子体丝起始位置是由整形飞秒脉冲的中心峰值强度和包络分布决定的。 相似文献
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频谱可调制的太赫兹波具有广泛的应用价值。利用一台纯相位式的液晶空间光调制器对飞秒激光脉冲进行空间整形,通过改变飞秒激光脉冲的横向空间分布,实现太赫兹波频谱的调制。在实验中,利用光泵浦整流方式产生太赫兹波,并利用太赫兹时域光谱系统对太赫兹信号进行探测。通过GS算法在液晶空间光调制器上加载不同的相位图,获得了不同的飞秒激光脉冲横向空间分布。通过改变探测距离和飞秒脉冲的空间分布参数,实现了太赫兹波频谱的调制。还利用菲涅尔衍射算法对这一过程进行了理论模拟,理论模拟结果与实验结果吻合的较好,这充分说明了基于飞秒脉冲空间整形的太赫兹光谱调制技术的可行性。 相似文献
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研制了一套基于多光子脉冲内干涉相位扫描方法的可以同时对飞秒激光脉冲进行相位测量和补偿的实验系统装置.实验中,通过自主研发的LabVIEW程序控制液晶空间光调制器和光纤光谱仪,对待测飞秒激光脉冲施加相位扫描,并同时记录受到调制的飞秒激光脉冲的倍频光谱,得到了多光子脉冲内干涉相位扫描(MIIPS)轨迹图.通过MIIPS轨迹图的三次测量和迭代运算,还原出了经过预先啁啾调制的中心波长约为810 nm、重复频率为1 kHz的飞秒激光脉冲的光谱相位,测量精度在0.1 rad以内.根据测量结果,利用液晶空间光调制器对该飞秒激光脉冲进行相位补偿,得到了近似傅里叶变换极限的飞秒激光脉冲.这一装置将在多光子显微成像、脉冲整形、飞秒激光光谱学等众多领域发挥重要作用. 相似文献
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飞秒激光成丝超连续辐射具有高强度和高时空相干性等优点,作为一种超宽带光源在很多领域都具有广泛的应用前景.本文提出一种结合微透镜阵列的空间调制和基于液晶空间光调制器的时域整形的飞秒激光脉冲整形方式,利用基于遗传算法的反馈优化控制,实现了飞秒激光在熔融石英中成丝产生的超连续辐射强度的调制,得到了在一定范围内光谱强度可控的超连续辐射光谱;光谱的能量密度可以从0.03μJ/nm调制到0.09μJ/nm,其能量密度变化达到了初始值的3倍.计算了典型迭代代数对应的整形脉冲时域包络,分析了超连续光谱随迭代代数的演化趋势,结果表明,脉冲包络的峰值强度和波形分布是影响超连续光谱展宽和强度的主要物理原因. 相似文献
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提出了一种实现大行程飞秒激光脉冲对相位控制的方法。其设计思想是:在迈克耳孙干涉仪中,利用改变激光偏振态的方法改变输出两光束的光程差因子。在对He-Ne激光输出的两束光实现相位锁定的基础上,进而提出了一种可对于超短激光双脉冲相对相位差实现超大行程控制的方法。对He-Ne激光的动态相位锁定、以及飞秒激光脉冲对的相对相位差控制分别作了实验验证。对He-Ne激光的静态相位锁定结果表明干涉仪两臂光程差可以控制在纳米精度;而飞秒激光脉冲测量自相关曲线与理论拟合结果非常接近,经傅里叶变换可得到较好的单峰谱图。该系统能够在实验范围中几乎无行程限制地实现飞秒激光脉冲对的相对相位动态稳定控制。 相似文献
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A. Rodenberg S. Fechner F. Dimler D. J. Tannor T. Brixner 《Applied physics. B, Lasers and optics》2008,93(4):763-772
The characterization and interpretation of ultrashort laser pulses is most intuitive in the joint time–frequency domain, where
structures like multiple pulses become immediately apparent. For practical reasons, ultrafast femtosecond laser pulse shaping,
however, is commonly carried out in the frequency domain. Here we implement pulse shaping of optical fields defined in the
von Neumann representation, which is a joint time–frequency distribution with complex-valued Gaussian basis functions. We
discuss the feasibility as well as the principal limitations of this technique, show illustrative examples, and propose possible
applications in coherent control. 相似文献
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Jian-Ping Li Lian-Zhong Deng Ye Zheng Peng-Peng Ding Tian-Qing Jia Zhen-Rong Sun Jian-Rong Qiu Shi-An Zhang 《Frontiers of Physics》2020,15(2):22603-68
The spectral phase of the femtosecond laser field is an important parameter that affects the up-conversion(UC)luminescence efficiency of dopant lanthanide ions.In this work,we report an experi-mental study on controlling the UC lmiiinescence efficiency in Sm^3+:NaYF4 glass by 800-nm femtosec-ond laser pulse shaping using spectral phase modulation.The optimal phase control strategy efficiently enhances or suppresses the UC luminescence intensity.Based on the laser-power dependence of the UC luminescence intensity and its comparison with the luminescence spectrum under direct 266-nm fem-tosecond lciser irradiation,we propose herein an excitation model combining non-resonant two-photon absorption with resonance-media ted three-photon absorption to explain the experimental observations. 相似文献
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B. von Vacano J. Rehbinder T. Buckup M. Motzkus 《Applied physics. B, Lasers and optics》2008,91(2):213-217
Nonlinear vibrational spectroscopy using a single beam of femtosecond pulses from an unamplified fibre laser oscillator is
demonstrated. To achieve high spectral resolution and sensitive signal detection with the picojoule pulse energies available,
pulse shaping and integrated interferometric detection is employed. The spectroscopic technique used is coherent anti-Stokes
Raman scattering (CARS), which yields well-resolved spectra of molecular vibrations in the 100–350 cm-1 domain of halomethane samples in the liquid phase. We explore the implications of phase control for the interferometric detection
of weak signals. The presented combination of a fiber laser, pulse shaping and CARS microspectroscopy is a first example of
simplified schemes for compact and robust nonlinear spectroscopic detection and sensing, which is demonstrated exemplarily
by on-line monitoring of the chemical composition in a microfluidic flow cell.
PACS 42.55.Wd; 42.62.Fi; 78.47.Fg; 42.65.Dr; 82.80.Gk; 92.20.cn 相似文献
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Ultrafast optical pulse shaping: A tutorial review 总被引:2,自引:0,他引:2
Andrew M. Weiner 《Optics Communications》2011,284(15):3669-3692
This paper presents a tutorial on the field of femtosecond pulse shaping, a technology that enables generation of nearly arbitrary, user defined, ultrafast optical waveforms, with control of phase, amplitude, and polarization. The emphasis is on Fourier transform pulse shaping, the most widely applied technique. Selected pulse shaping applications are described, with specific discussion of coherent control of quantum and nonlinear processes and of lightwave communications. Two new areas of pulse shaping research, namely, hyperfine spectral resolution pulse shaping and pulse shaping applications in ultrabroadband RF photonics, are discussed and illustrated with examples taken from the author's laboratory. 相似文献