共查询到20条相似文献,搜索用时 46 毫秒
1.
We simulate multishot intensity-and-phase measurements of unstable trains of complex ultrashort pulses using second-harmonic-generation (SHG) frequency-resolved optical gating (FROG) and spectral-phase interferometry for direct electric-field reconstruction (SPIDER). Both techniques fail to see the pulse structure. But FROG yields the correct average pulse duration and suggests the instability by exhibiting significant disagreement between measured and retrieved traces. SPIDER retrieves the correct average spectral phase but significantly underestimates the average pulse duration. In short, SPIDER measures only the coherent artifact. An analytical calculation confirms this last fact. 相似文献
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We describe a new and simple method to aid in the analysis of retrieved pulses from inverted frequency-resolved optical gating (FROG) traces. The analysis can separate noise from distortion and shows that distortion is more deleterious to the retrieved pulse than is pure noise. The analysis relies on the fact that FROG traces can be constructed from a single outer product of two vectors, whereas distortion and noise require the sum of a series of outer products. 相似文献
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飞秒激光在激光核聚变、卫星精密测距、激光微加工等领域具有重要的应用前景,同时也是产生太赫兹波的主要泵浦源。介绍了国内外飞秒激光脉冲宽度和脉冲波形的测试方法,比较了自相关法、频率分辨光学快门法、光谱相位相干直接电场重构法的优缺点。自相关法具有脉宽测量范围广、结构简单等特点,但不具备脉冲波形测试能力。光谱相位相干直接电场重构法对待测激光光束质量要求较高, 不适合大量程范围激光脉宽快速测量。为满足10 fs~5 ps大量程范围超短激光脉冲宽度和脉冲波形的测试需求,采用自相关法及二次谐波频率分辨光学开关法研制飞秒激光脉冲宽度和脉冲波形测试仪,时间分辨率优于2 fs。 相似文献
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S. Yeremenko A. Baltu?ka M.S. Pshenichnikov D.A. Wiersma 《Applied physics. B, Lasers and optics》2000,70(7):S109-S117
We propose a new criterion for the assessment of ultrashort pulse reconstruction quality. Our idea is based on the use of a two-dimensional Wigner representation of the electric field. This allows introducing a single measure to represent the quality of both phase and amplitude retrieval. The new criterion is employed to examine two contemporary pulse characterization techniques: FROG (Frequency Resolved Optical Gating) and SPIDER (Spectral Interferometry for Direct Electric-field Reconstruction). For SPIDER, the influence of reference pulse stretching on the quality of phase extraction is investigated. Next, we ascertain the limitations in the use of a Fabri-Perrot etalon in the SPIDER apparatus for producing delayed pulse replicas. For the FROG technique we examine the impact of the doubling crystal orientation on the quality of the amplitude-phase retrieval of sub-5-fs pulses. The introduced criterion is also applied to study the respective sensitivity of FROG and SPIDERto the limited phase-matching bandwidth of the non-linear medium and detector noise. 相似文献
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We construct field shapes with distinct amplitude profiles that have nearly identical second-harmonic generation frequency-resolved optical gating (SHG FROG) traces. Although such fields are not true mathematical ambiguities, they result in experimentally indistinguishable FROG traces. These fields are neither time-reversed copies nor pulselets with a mere relative phase difference, which are well known nontrivial ambiguities for SHG FROG. We also show that for certain example fields, second-order interferometric autocorrelation is more sensitive to the pulse shape than is SHG FROG. 相似文献
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Doubled femtosecond laser pulses in-line are needed in the collinear pump-probe technique, collinear second harmonic generation frequency-resolved optical gating (SHG FROG) and the spectral phase interferometry for direct electric-field reconstruction (SPIDER), etc. Normally, it is generated by using a Michelson's structure. In this paper, we proposed a novel structure with two-layered reflective Dammann gratings and the reflective mirrors to generate doubled femtosecond laser pulses in line without transmission optical elements. Angular dispersion and spectral spatial walk-off are both compensated. In addition, this structure can also compress the positive chirped pulse, which cannot be realized with a Michelson's structure. By adopting triangular grating and blazed gratings, the efficiency of the system would in principle be increased as the Michelson's scheme. Experiments demonstrated that this method should be an alternative approach for generation of the double compressed pulses of femtosecond laser for practical applications. 相似文献
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《Comptes Rendus de l''Academie des Sciences Series IV Physics》2001,2(10):1415-1426
The complete characterization of a short light pulse requires the measurement of the value of the electric field as a function of time, or conversely, as a function of the optical frequency. Many different techniques have been demonstrated for this purpose. They fall in two main categories, whether a known reference pulse whose spectrum encompasses that of the unknown pulse is available or not. In the first case, linear techniques such as time-domain or frequency-domain interferometry can be directly used, with the advantage of a high sensitivity. In the latter case, non-stationary filters can be implemented using optical non-linearities, in techniques such as Frequency Resolved Optical Gating (FROG) or Spectral Phase Interferometry for Direct Electric-field Reconstruction (SPIDER). 相似文献
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We report a new version of spectral phase interferometry for direct electric field reconstruction (SPIDER) requiring only a single phase-shaped laser beam. A narrowband probe pulse is selected out of a broadband ultrafast laser pulse by a phase pulse-shaping technique and mixed with the original broadband pulse to generate a second-harmonic generation (SHG) signal. Using another SHG signal solely generated by the broadband pulse as a local oscillator, the spectral phase of the broadband laser pulse can be analytically retrieved by a combination of double-quadrature spectral interferometry and homodyne optical technique for SPIDER (HOT SPIDER). An arbitrary spectral phase at the sample position of a microscope can be compensated with a precision of 0.05 rad over the FWHM of the laser spectrum. It is readily applicable to a nonlinear microscopy technique with a phase-controlled broadband laser pulse. 相似文献
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提出一种新的诊断飞秒脉冲振幅与位相的高精度测量方法.该方法发展了传统的SPIDER方法,保留了原方法对脉冲信息可以实时、有效和全面地测取的优点,并能克服其不能测量脉宽较大或位相信息复杂的脉冲的缺点.在新方法中和频后的脉冲对没有相对延时,形成无干涉条纹的剪切干涉图.在调节一个小量延时于某些特定值,可去掉剪切干涉图的歧义性.给出数值模拟结果,证明此方法无需经过傅里叶变换滤波,可直接由干涉图唯一地提取出脉冲的振幅与位相信息.
关键词:
光谱位相相干直接电场重构法
飞秒脉冲测量
超快信息光学 相似文献
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Numerical simulation for characterizing femtosecond optical pulses with the SPIDER algorithm 下载免费PDF全文
In this article based on the spectral phase interferometry for direct electric-field reconstruction (SPIDER), the femtosecond pulses with various phase characters are numerically simulated. The spectral phases and amplitudes of the transform-limited pulse, the linear chirped pulse, the cubic dispersion pulse, the quartic dispersion pulse, the self-phase modulation pulse and the pulses with the combination of different chirped characters are retrieved. These characterized pulses are applicable to the real-time measurement as samples for diagnosing the chirped characters of pulses quickly. 相似文献
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We present what we believe to be a new version of spectral phase interferometry for direct electric field reconstruction (SPIDER) using only a single-phase and polarization controlled laser beam. Two narrow pulses and one broadband pulse are selected out of an ultrafast laser pulse by a polarization and phase control technique to generate second harmonic generation (SHG) signals, which are equivalent to a spectral shear interferogram in the conventional SPIDER method. The spectral phase of the broadband laser pulse is extracted analytically with double quadrature spectral interferometry (DQSI). An arbitrary spectral phase can be retrieved with great precision and compensated in situ at the sample position of a microscope. This new method requires no separate reference beam and is suitable for nonlinear optical microscopy with a phase controlled laser pulse. 相似文献
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Spatially resolved amplitude and phase characterization of femtosecond optical pulses 总被引:5,自引:0,他引:5
Gallmann L Steinmeyer G Sutter DH Rupp T Iaconis C Walmsley IA Keller U 《Optics letters》2001,26(2):96-98
Ultrabroadband pulses exhibit a frequency-dependent mode size owing to the wavelength dependence of free-space diffraction. Additionally, rather complex lateral dependence of the temporal pulse shape has been reported for Kerr-lens mode-locked lasers and broadband amplifier chains and in frequency-domain pulse shapers, for example. We demonstrate an ultrashort-pulse characterization technique that reveals lateral pulse-shape variations by spatially resolved amplitude and phase measurements by use of spectral phase interferometry for direct electric-field reconstruction (SPIDER). Unlike with autocorrelation techniques, with SPIDER we can obtain spatially resolved pulse characterization even after the nonlinear process. Thus, with this method the spectral phase of the pulse can be resolved very rapidly along one lateral beam axis in a single measurement. 相似文献
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从光谱位相相干电场重构法(SPIDER)的原理出发,实现了算法、讨论时间延迟、光谱剪切量、滤波窗口宽度、色散量等几个方面的优化选取。当展宽器色散和脉冲宽度一定时,脉冲对的时间延迟存在一个最佳取值范围。相对光谱剪切量在5%~15%间,滤波窗口宽度为/3,重构出的位相误差最小。对干涉图取平均来减小噪声的影响。用SPIDER算法还原了脉冲的电场和位相信息,由SPIDER测量的脉冲宽度为17.7 fs。同时为了比较,用自相关法测量了同一脉冲,由自相关曲线可估算出脉冲宽度为16.8 fs,与SPIDER 的误差比为5.1%,说明了实验的有效性。 相似文献
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A. Efimov M.D. Moores B. Mei J.L. Krause C.W. Siders D.H. Reitze 《Applied physics. B, Lasers and optics》2000,70(7):S133-S141
Minimizing residual frequency dispersion that accompanies pulse stretching, amplification, and recompression is an important consideration in ultrashort chirped-pulse amplifiers. Here we show how an adaptive learning algorithm can be used in conjunction with a pulse shaper to compensate for higher-order and nonlinear dispersion in a chirped-pulse amplifier. Using spectral blueshifting as a sensitive diagnostic for pulse shape, we implement a 'learning loop' comprised of the pulse shaper, strong field laser ionization, and a genetic algorithm to minimize dispersion through the amplifier. We verify our optimization results using frequency-resolved optical gating (FROG) measurements and also show theoretically and experimentally that spectral blueshifting is indeed a sensitive diagnostic for pulse shape, and specifically, for higher-order dispersion. 相似文献